% Generated using the yosys 'help -write-tex-command-reference-manual' command. \section{abc -- use ABC for technology mapping} \label{cmd:abc} \begin{lstlisting}[numbers=left,frame=single] abc [options] [selection] This pass uses the ABC tool [1] for technology mapping of yosys's internal gate library to a target architecture. -exe <command> use the specified command instead of "<yosys-bindir>/yosys-abc" to execute ABC. This can e.g. be used to call a specific version of ABC or a wrapper. -script <file> use the specified ABC script file instead of the default script. if <file> starts with a plus sign (+), then the rest of the filename string is interpreted as the command string to be passed to ABC. The leading plus sign is removed and all commas (,) in the string are replaced with blanks before the string is passed to ABC. if no -script parameter is given, the following scripts are used: for -liberty without -constr: strash; ifraig; scorr; dc2; dretime; strash; &get -n; &dch -f; &nf {D}; &put for -liberty with -constr: strash; ifraig; scorr; dc2; dretime; strash; &get -n; &dch -f; &nf {D}; &put; buffer; upsize {D}; dnsize {D}; stime -p for -lut/-luts (only one LUT size): strash; ifraig; scorr; dc2; dretime; strash; dch -f; if; mfs2; lutpack {S} for -lut/-luts (different LUT sizes): strash; ifraig; scorr; dc2; dretime; strash; dch -f; if; mfs2 for -sop: strash; ifraig; scorr; dc2; dretime; strash; dch -f; cover {I} {P} otherwise: strash; ifraig; scorr; dc2; dretime; strash; &get -n; &dch -f; &nf {D}; &put -fast use different default scripts that are slightly faster (at the cost of output quality): for -liberty without -constr: strash; dretime; map {D} for -liberty with -constr: strash; dretime; map {D}; buffer; upsize {D}; dnsize {D}; stime -p for -lut/-luts: strash; dretime; if for -sop: strash; dretime; cover -I {I} -P {P} otherwise: strash; dretime; map -liberty <file> generate netlists for the specified cell library (using the liberty file format). -constr <file> pass this file with timing constraints to ABC. use with -liberty. a constr file contains two lines: set_driving_cell <cell_name> set_load <floating_point_number> the set_driving_cell statement defines which cell type is assumed to drive the primary inputs and the set_load statement sets the load in femtofarads for each primary output. -D <picoseconds> set delay target. the string {D} in the default scripts above is replaced by this option when used, and an empty string otherwise. this also replaces 'dretime' with 'dretime; retime -o {D}' in the default scripts above. -I <num> maximum number of SOP inputs. (replaces {I} in the default scripts above) -P <num> maximum number of SOP products. (replaces {P} in the default scripts above) -S <num> maximum number of LUT inputs shared. (replaces {S} in the default scripts above, default: -S 1) -lut <width> generate netlist using luts of (max) the specified width. -lut <w1>:<w2> generate netlist using luts of (max) the specified width <w2>. All luts with width <= <w1> have constant cost. for luts larger than <w1> the area cost doubles with each additional input bit. the delay cost is still constant for all lut widths. -luts <cost1>,<cost2>,<cost3>,<sizeN>:<cost4-N>,.. generate netlist using luts. Use the specified costs for luts with 1, 2, 3, .. inputs. -sop map to sum-of-product cells and inverters -g type1,type2,... Map to the specified list of gate types. Supported gates types are: AND, NAND, OR, NOR, XOR, XNOR, ANDNOT, ORNOT, MUX, AOI3, OAI3, AOI4, OAI4. (The NOT gate is always added to this list automatically.) The following aliases can be used to reference common sets of gate types: simple: AND OR XOR MUX cmos2: NAND NOR cmos3: NAND NOR AOI3 OAI3 cmos4: NAND NOR AOI3 OAI3 AOI4 OAI4 gates: AND NAND OR NOR XOR XNOR ANDNOT ORNOT aig: AND NAND OR NOR ANDNOT ORNOT Prefix a gate type with a '-' to remove it from the list. For example the arguments 'AND,OR,XOR' and 'simple,-MUX' are equivalent. -dff also pass $_DFF_?_ and $_DFFE_??_ cells through ABC. modules with many clock domains are automatically partitioned in clock domains and each domain is passed through ABC independently. -clk [!]<clock-signal-name>[,[!]<enable-signal-name>] use only the specified clock domain. this is like -dff, but only FF cells that belong to the specified clock domain are used. -keepff set the "keep" attribute on flip-flop output wires. (and thus preserve them, for example for equivalence checking.) -nocleanup when this option is used, the temporary files created by this pass are not removed. this is useful for debugging. -showtmp print the temp dir name in log. usually this is suppressed so that the command output is identical across runs. -markgroups set a 'abcgroup' attribute on all objects created by ABC. The value of this attribute is a unique integer for each ABC process started. This is useful for debugging the partitioning of clock domains. When neither -liberty nor -lut is used, the Yosys standard cell library is loaded into ABC before the ABC script is executed. Note that this is a logic optimization pass within Yosys that is calling ABC internally. This is not going to "run ABC on your design". It will instead run ABC on logic snippets extracted from your design. You will not get any useful output when passing an ABC script that writes a file. Instead write your full design as BLIF file with write_blif and the load that into ABC externally if you want to use ABC to convert your design into another format. [1] http://www.eecs.berkeley.edu/~alanmi/abc/ \end{lstlisting} \section{add -- add objects to the design} \label{cmd:add} \begin{lstlisting}[numbers=left,frame=single] add <command> [selection] This command adds objects to the design. It operates on all fully selected modules. So e.g. 'add -wire foo' will add a wire foo to all selected modules. add {-wire|-input|-inout|-output} <name> <width> [selection] Add a wire (input, inout, output port) with the given name and width. The command will fail if the object exists already and has different properties than the object to be created. add -global_input <name> <width> [selection] Like 'add -input', but also connect the signal between instances of the selected modules. \end{lstlisting} \section{aigmap -- map logic to and-inverter-graph circuit} \label{cmd:aigmap} \begin{lstlisting}[numbers=left,frame=single] aigmap [options] [selection] Replace all logic cells with circuits made of only $_AND_ and $_NOT_ cells. -nand Enable creation of $_NAND_ cells \end{lstlisting} \section{alumacc -- extract ALU and MACC cells} \label{cmd:alumacc} \begin{lstlisting}[numbers=left,frame=single] alumacc [selection] This pass translates arithmetic operations like $add, $mul, $lt, etc. to $alu and $macc cells. \end{lstlisting} \section{assertpmux -- convert internal signals to module ports} \label{cmd:assertpmux} \begin{lstlisting}[numbers=left,frame=single] assertpmux [options] [selection] This command adds asserts to the design that assert that all parallel muxes ($pmux cells) have a maximum of one of their inputs enable at any time. -noinit do not enforce the pmux condition during the init state -always usually the $pmux condition is only checked when the $pmux output is used be the mux tree it drives. this option will deactivate this additional constrained and check the $pmux condition always. \end{lstlisting} \section{async2sync -- convert async FF inputs to sync circuits} \label{cmd:async2sync} \begin{lstlisting}[numbers=left,frame=single] async2sync [options] [selection] This command replaces async FF inputs with sync circuits emulating the same behavior for when the async signals are actually synchronized to the clock. This pass assumes negative hold time for the async FF inputs. For example when a reset deasserts with the clock edge, then the FF output will still drive the reset value in the next cycle regardless of the data-in value at the time of the clock edge. Currently only $adff cells are supported by this pass. \end{lstlisting} \section{attrmap -- renaming attributes} \label{cmd:attrmap} \begin{lstlisting}[numbers=left,frame=single] attrmap [options] [selection] This command renames attributes and/or mapps key/value pairs to other key/value pairs. -tocase <name> Match attribute names case-insensitively and set it to the specified name. -rename <old_name> <new_name> Rename attributes as specified -map <old_name>=<old_value> <new_name>=<new_value> Map key/value pairs as indicated. -imap <old_name>=<old_value> <new_name>=<new_value> Like -map, but use case-insensitive match for <old_value> when it is a string value. -remove <name>=<value> Remove attributes matching this pattern. -modattr Operate on module attributes instead of attributes on wires and cells. For example, mapping Xilinx-style "keep" attributes to Yosys-style: attrmap -tocase keep -imap keep="true" keep=1 \ -imap keep="false" keep=0 -remove keep=0 \end{lstlisting} \section{attrmvcp -- move or copy attributes from wires to driving cells} \label{cmd:attrmvcp} \begin{lstlisting}[numbers=left,frame=single] attrmvcp [options] [selection] Move or copy attributes on wires to the cells driving them. -copy By default, attributes are moved. This will only add the attribute to the cell, without removing it from the wire. -purge If no selected cell consumes the attribute, then it is left on the wire by default. This option will cause the attribute to be removed from the wire, even if no selected cell takes it. -driven By default, attriburtes are moved to the cell driving the wire. With this option set it will be moved to the cell driven by the wire instead. -attr <attrname> Move or copy this attribute. This option can be used multiple times. \end{lstlisting} \section{blackbox -- change type of cells in the design} \label{cmd:blackbox} \begin{lstlisting}[numbers=left,frame=single] blackbox [options] [selection] Convert modules into blackbox modules (remove contents and set the blackbox module attribute). \end{lstlisting} \section{cd -- a shortcut for 'select -module <name>'} \label{cmd:cd} \begin{lstlisting}[numbers=left,frame=single] cd <modname> This is just a shortcut for 'select -module <modname>'. cd <cellname> When no module with the specified name is found, but there is a cell with the specified name in the current module, then this is equivalent to 'cd <celltype>'. cd .. Remove trailing substrings that start with '.' in current module name until the name of a module in the current design is generated, then switch to that module. Otherwise clear the current selection. cd This is just a shortcut for 'select -clear'. \end{lstlisting} \section{check -- check for obvious problems in the design} \label{cmd:check} \begin{lstlisting}[numbers=left,frame=single] check [options] [selection] This pass identifies the following problems in the current design: - combinatorial loops - two or more conflicting drivers for one wire - used wires that do not have a driver When called with -noinit then this command also checks for wires which have the 'init' attribute set. When called with -initdrv then this command also checks for wires which have the 'init' attribute set and aren't driven by a FF cell type. When called with -assert then the command will produce an error if any problems are found in the current design. \end{lstlisting} \section{chformal -- change formal constraints of the design} \label{cmd:chformal} \begin{lstlisting}[numbers=left,frame=single] chformal [types] [mode] [options] [selection] Make changes to the formal constraints of the design. The [types] options the type of constraint to operate on. If none of the folling options is given, the command will operate on all constraint types: -assert $assert cells, representing assert(...) constraints -assume $assume cells, representing assume(...) constraints -live $live cells, representing assert(s_eventually ...) -fair $fair cells, representing assume(s_eventually ...) -cover $cover cells, representing cover() statements Exactly one of the following modes must be specified: -remove remove the cells and thus constraints from the design -early bypass FFs that only delay the activation of a constraint -delay <N> delay activation of the constraint by <N> clock cycles -skip <N> ignore activation of the constraint in the first <N> clock cycles -assert2assume -assume2assert -live2fair -fair2live change the roles of cells as indicated. this options can be combined \end{lstlisting} \section{chparam -- re-evaluate modules with new parameters} \label{cmd:chparam} \begin{lstlisting}[numbers=left,frame=single] chparam [ -set name value ]... [selection] Re-evaluate the selected modules with new parameters. String values must be passed in double quotes ("). chparam -list [selection] List the available parameters of the selected modules. \end{lstlisting} \section{chtype -- change type of cells in the design} \label{cmd:chtype} \begin{lstlisting}[numbers=left,frame=single] chtype [options] [selection] Change the types of cells in the design. -set <type> set the cell type to the given type -map <old_type> <new_type> change cells types that match <old_type> to <new_type> \end{lstlisting} \section{clean -- remove unused cells and wires} \label{cmd:clean} \begin{lstlisting}[numbers=left,frame=single] clean [options] [selection] This is identical to 'opt_clean', but less verbose. When commands are separated using the ';;' token, this command will be executed between the commands. When commands are separated using the ';;;' token, this command will be executed in -purge mode between the commands. \end{lstlisting} \section{clk2fflogic -- convert clocked FFs to generic \$ff cells} \label{cmd:clk2fflogic} \begin{lstlisting}[numbers=left,frame=single] clk2fflogic [options] [selection] This command replaces clocked flip-flops with generic $ff cells that use the implicit global clock. This is useful for formal verification of designs with multiple clocks. \end{lstlisting} \section{connect -- create or remove connections} \label{cmd:connect} \begin{lstlisting}[numbers=left,frame=single] connect [-nomap] [-nounset] -set <lhs-expr> <rhs-expr> Create a connection. This is equivalent to adding the statement 'assign <lhs-expr> = <rhs-expr>;' to the Verilog input. Per default, all existing drivers for <lhs-expr> are unconnected. This can be overwritten by using the -nounset option. connect [-nomap] -unset <expr> Unconnect all existing drivers for the specified expression. connect [-nomap] -port <cell> <port> <expr> Connect the specified cell port to the specified cell port. Per default signal alias names are resolved and all signal names are mapped the the signal name of the primary driver. Using the -nomap option deactivates this behavior. The connect command operates in one module only. Either only one module must be selected or an active module must be set using the 'cd' command. This command does not operate on module with processes. \end{lstlisting} \section{connwrappers -- match width of input-output port pairs} \label{cmd:connwrappers} \begin{lstlisting}[numbers=left,frame=single] connwrappers [options] [selection] Wrappers are used in coarse-grain synthesis to wrap cells with smaller ports in wrapper cells with a (larger) constant port size. I.e. the upper bits of the wrapper output are signed/unsigned bit extended. This command uses this knowledge to rewire the inputs of the driven cells to match the output of the driving cell. -signed <cell_type> <port_name> <width_param> -unsigned <cell_type> <port_name> <width_param> consider the specified signed/unsigned wrapper output -port <cell_type> <port_name> <width_param> <sign_param> use the specified parameter to decide if signed or unsigned The options -signed, -unsigned, and -port can be specified multiple times. \end{lstlisting} \section{coolrunner2\_sop -- break \$sop cells into ANDTERM/ORTERM cells} \label{cmd:coolrunner2_sop} \begin{lstlisting}[numbers=left,frame=single] coolrunner2_sop [options] [selection] Break $sop cells into ANDTERM/ORTERM cells. \end{lstlisting} \section{copy -- copy modules in the design} \label{cmd:copy} \begin{lstlisting}[numbers=left,frame=single] copy old_name new_name Copy the specified module. Note that selection patterns are not supported by this command. \end{lstlisting} \section{cover -- print code coverage counters} \label{cmd:cover} \begin{lstlisting}[numbers=left,frame=single] cover [options] [pattern] Print the code coverage counters collected using the cover() macro in the Yosys C++ code. This is useful to figure out what parts of Yosys are utilized by a test bench. -q Do not print output to the normal destination (console and/or log file) -o file Write output to this file, truncate if exists. -a file Write output to this file, append if exists. -d dir Write output to a newly created file in the specified directory. When one or more pattern (shell wildcards) are specified, then only counters matching at least one pattern are printed. It is also possible to instruct Yosys to print the coverage counters on program exit to a file using environment variables: YOSYS_COVER_DIR="{dir-name}" yosys {args} This will create a file (with an auto-generated name) in this directory and write the coverage counters to it. YOSYS_COVER_FILE="{file-name}" yosys {args} This will append the coverage counters to the specified file. Hint: Use the following AWK command to consolidate Yosys coverage files: gawk '{ p[$3] = $1; c[$3] += $2; } END { for (i in p) printf "%-60s %10d %s\n", p[i], c[i], i; }' {files} | sort -k3 Coverage counters are only available in Yosys for Linux. \end{lstlisting} \section{delete -- delete objects in the design} \label{cmd:delete} \begin{lstlisting}[numbers=left,frame=single] delete [selection] Deletes the selected objects. This will also remove entire modules, if the whole module is selected. delete {-input|-output|-port} [selection] Does not delete any object but removes the input and/or output flag on the selected wires, thus 'deleting' module ports. \end{lstlisting} \section{deminout -- demote inout ports to input or output} \label{cmd:deminout} \begin{lstlisting}[numbers=left,frame=single] deminout [options] [selection] "Demote" inout ports to input or output ports, if possible. \end{lstlisting} \section{design -- save, restore and reset current design} \label{cmd:design} \begin{lstlisting}[numbers=left,frame=single] design -reset Clear the current design. design -save <name> Save the current design under the given name. design -stash <name> Save the current design under the given name and then clear the current design. design -push Push the current design to the stack and then clear the current design. design -pop Reset the current design and pop the last design from the stack. design -load <name> Reset the current design and load the design previously saved under the given name. design -copy-from <name> [-as <new_mod_name>] <selection> Copy modules from the specified design into the current one. The selection is evaluated in the other design. design -copy-to <name> [-as <new_mod_name>] [selection] Copy modules from the current design into the specified one. design -import <name> [-as <new_top_name>] [selection] Import the specified design into the current design. The source design must either have a selected top module or the selection must contain exactly one module that is then used as top module for this command. design -reset-vlog The Verilog front-end remembers defined macros and top-level declarations between calls to 'read_verilog'. This command resets this memory. \end{lstlisting} \section{dff2dffe -- transform \$dff cells to \$dffe cells} \label{cmd:dff2dffe} \begin{lstlisting}[numbers=left,frame=single] dff2dffe [options] [selection] This pass transforms $dff cells driven by a tree of multiplexers with one or more feedback paths to $dffe cells. It also works on gate-level cells such as $_DFF_P_, $_DFF_N_ and $_MUX_. -unmap operate in the opposite direction: replace $dffe cells with combinations of $dff and $mux cells. the options below are ignore in unmap mode. -direct <internal_gate_type> <external_gate_type> map directly to external gate type. <internal_gate_type> can be any internal gate-level FF cell (except $_DFFE_??_). the <external_gate_type> is the cell type name for a cell with an identical interface to the <internal_gate_type>, except it also has an high-active enable port 'E'. Usually <external_gate_type> is an intermediate cell type that is then translated to the final type using 'techmap'. -direct-match <pattern> like -direct for all DFF cell types matching the expression. this will use $__DFFE_* as <external_gate_type> matching the internal gate type $_DFF_*_, and $__DFFSE_* for those matching $_DFFS_*_, except for $_DFF_[NP]_, which is converted to $_DFFE_[NP]_. \end{lstlisting} \section{dff2dffs -- process sync set/reset with SR over CE priority} \label{cmd:dff2dffs} \begin{lstlisting}[numbers=left,frame=single] dff2dffs [options] [selection] Merge synchronous set/reset $_MUX_ cells to create $__DFFS_[NP][NP][01], to be run before dff2dffe for SR over CE priority. \end{lstlisting} \section{dffinit -- set INIT param on FF cells} \label{cmd:dffinit} \begin{lstlisting}[numbers=left,frame=single] dffinit [options] [selection] This pass sets an FF cell parameter to the the initial value of the net it drives. (This is primarily used in FPGA flows.) -ff <cell_name> <output_port> <init_param> operate on the specified cell type. this option can be used multiple times. -highlow use the string values "high" and "low" to represent a single-bit initial value of 1 or 0. (multi-bit values are not supported in this mode.) \end{lstlisting} \section{dfflibmap -- technology mapping of flip-flops} \label{cmd:dfflibmap} \begin{lstlisting}[numbers=left,frame=single] dfflibmap [-prepare] -liberty <file> [selection] Map internal flip-flop cells to the flip-flop cells in the technology library specified in the given liberty file. This pass may add inverters as needed. Therefore it is recommended to first run this pass and then map the logic paths to the target technology. When called with -prepare, this command will convert the internal FF cells to the internal cell types that best match the cells found in the given liberty file. \end{lstlisting} \section{dffsr2dff -- convert DFFSR cells to simpler FF cell types} \label{cmd:dffsr2dff} \begin{lstlisting}[numbers=left,frame=single] dffsr2dff [options] [selection] This pass converts DFFSR cells ($dffsr, $_DFFSR_???_) and ADFF cells ($adff, $_DFF_???_) to simpler FF cell types when any of the set/reset inputs is unused. \end{lstlisting} \section{dump -- print parts of the design in ilang format} \label{cmd:dump} \begin{lstlisting}[numbers=left,frame=single] dump [options] [selection] Write the selected parts of the design to the console or specified file in ilang format. -m also dump the module headers, even if only parts of a single module is selected -n only dump the module headers if the entire module is selected -o <filename> write to the specified file. -a <filename> like -outfile but append instead of overwrite \end{lstlisting} \section{echo -- turning echoing back of commands on and off} \label{cmd:echo} \begin{lstlisting}[numbers=left,frame=single] echo on Print all commands to log before executing them. echo off Do not print all commands to log before executing them. (default) \end{lstlisting} \section{edgetypes -- list all types of edges in selection} \label{cmd:edgetypes} \begin{lstlisting}[numbers=left,frame=single] edgetypes [options] [selection] This command lists all unique types of 'edges' found in the selection. An 'edge' is a 4-tuple of source and sink cell type and port name. \end{lstlisting} \section{equiv\_add -- add a \$equiv cell} \label{cmd:equiv_add} \begin{lstlisting}[numbers=left,frame=single] equiv_add [-try] gold_sig gate_sig This command adds an $equiv cell for the specified signals. equiv_add [-try] -cell gold_cell gate_cell This command adds $equiv cells for the ports of the specified cells. \end{lstlisting} \section{equiv\_induct -- proving \$equiv cells using temporal induction} \label{cmd:equiv_induct} \begin{lstlisting}[numbers=left,frame=single] equiv_induct [options] [selection] Uses a version of temporal induction to prove $equiv cells. Only selected $equiv cells are proven and only selected cells are used to perform the proof. -undef enable modelling of undef states -seq <N> the max. number of time steps to be considered (default = 4) This command is very effective in proving complex sequential circuits, when the internal state of the circuit quickly propagates to $equiv cells. However, this command uses a weak definition of 'equivalence': This command proves that the two circuits will not diverge after they produce equal outputs (observable points via $equiv) for at least <N> cycles (the <N> specified via -seq). Combined with simulation this is very powerful because simulation can give you confidence that the circuits start out synced for at least <N> cycles after reset. \end{lstlisting} \section{equiv\_make -- prepare a circuit for equivalence checking} \label{cmd:equiv_make} \begin{lstlisting}[numbers=left,frame=single] equiv_make [options] gold_module gate_module equiv_module This creates a module annotated with $equiv cells from two presumably equivalent modules. Use commands such as 'equiv_simple' and 'equiv_status' to work with the created equivalent checking module. -inames Also match cells and wires with $... names. -blacklist <file> Do not match cells or signals that match the names in the file. -encfile <file> Match FSM encodings using the description from the file. See 'help fsm_recode' for details. Note: The circuit created by this command is not a miter (with something like a trigger output), but instead uses $equiv cells to encode the equivalence checking problem. Use 'miter -equiv' if you want to create a miter circuit. \end{lstlisting} \section{equiv\_mark -- mark equivalence checking regions} \label{cmd:equiv_mark} \begin{lstlisting}[numbers=left,frame=single] equiv_mark [options] [selection] This command marks the regions in an equivalence checking module. Region 0 is the proven part of the circuit. Regions with higher numbers are connected unproven subcricuits. The integer attribute 'equiv_region' is set on all wires and cells. \end{lstlisting} \section{equiv\_miter -- extract miter from equiv circuit} \label{cmd:equiv_miter} \begin{lstlisting}[numbers=left,frame=single] equiv_miter [options] miter_module [selection] This creates a miter module for further analysis of the selected $equiv cells. -trigger Create a trigger output -cmp Create cmp_* outputs for individual unproven $equiv cells -assert Create a $assert cell for each unproven $equiv cell -undef Create compare logic that handles undefs correctly \end{lstlisting} \section{equiv\_purge -- purge equivalence checking module} \label{cmd:equiv_purge} \begin{lstlisting}[numbers=left,frame=single] equiv_purge [options] [selection] This command removes the proven part of an equivalence checking module, leaving only the unproven segments in the design. This will also remove and add module ports as needed. \end{lstlisting} \section{equiv\_remove -- remove \$equiv cells} \label{cmd:equiv_remove} \begin{lstlisting}[numbers=left,frame=single] equiv_remove [options] [selection] This command removes the selected $equiv cells. If neither -gold nor -gate is used then only proven cells are removed. -gold keep gold circuit -gate keep gate circuit \end{lstlisting} \section{equiv\_simple -- try proving simple \$equiv instances} \label{cmd:equiv_simple} \begin{lstlisting}[numbers=left,frame=single] equiv_simple [options] [selection] This command tries to prove $equiv cells using a simple direct SAT approach. -v verbose output -undef enable modelling of undef states -short create shorter input cones that stop at shared nodes. This yields simpler SAT problems but sometimes fails to prove equivalence. -nogroup disabling grouping of $equiv cells by output wire -seq <N> the max. number of time steps to be considered (default = 1) \end{lstlisting} \section{equiv\_status -- print status of equivalent checking module} \label{cmd:equiv_status} \begin{lstlisting}[numbers=left,frame=single] equiv_status [options] [selection] This command prints status information for all selected $equiv cells. -assert produce an error if any unproven $equiv cell is found \end{lstlisting} \section{equiv\_struct -- structural equivalence checking} \label{cmd:equiv_struct} \begin{lstlisting}[numbers=left,frame=single] equiv_struct [options] [selection] This command adds additional $equiv cells based on the assumption that the gold and gate circuit are structurally equivalent. Note that this can introduce bad $equiv cells in cases where the netlists are not structurally equivalent, for example when analyzing circuits with cells with commutative inputs. This command will also de-duplicate gates. -fwd by default this command performans forward sweeps until nothing can be merged by forwards sweeps, then backward sweeps until forward sweeps are effective again. with this option set only forward sweeps are performed. -fwonly <cell_type> add the specified cell type to the list of cell types that are only merged in forward sweeps and never in backward sweeps. $equiv is in this list automatically. -icells by default, the internal RTL and gate cell types are ignored. add this option to also process those cell types with this command. -maxiter <N> maximum number of iterations to run before aborting \end{lstlisting} \section{eval -- evaluate the circuit given an input} \label{cmd:eval} \begin{lstlisting}[numbers=left,frame=single] eval [options] [selection] This command evaluates the value of a signal given the value of all required inputs. -set <signal> <value> set the specified signal to the specified value. -set-undef set all unspecified source signals to undef (x) -table <signal> create a truth table using the specified input signals -show <signal> show the value for the specified signal. if no -show option is passed then all output ports of the current module are used. \end{lstlisting} \section{expose -- convert internal signals to module ports} \label{cmd:expose} \begin{lstlisting}[numbers=left,frame=single] expose [options] [selection] This command exposes all selected internal signals of a module as additional outputs. -dff only consider wires that are directly driven by register cell. -cut when exposing a wire, create an input/output pair and cut the internal signal path at that wire. -input when exposing a wire, create an input port and disconnect the internal driver. -shared only expose those signals that are shared among the selected modules. this is useful for preparing modules for equivalence checking. -evert also turn connections to instances of other modules to additional inputs and outputs and remove the module instances. -evert-dff turn flip-flops to sets of inputs and outputs. -sep <separator> when creating new wire/port names, the original object name is suffixed with this separator (default: '.') and the port name or a type designator for the exposed signal. \end{lstlisting} \section{extract -- find subcircuits and replace them with cells} \label{cmd:extract} \begin{lstlisting}[numbers=left,frame=single] extract -map <map_file> [options] [selection] extract -mine <out_file> [options] [selection] This pass looks for subcircuits that are isomorphic to any of the modules in the given map file and replaces them with instances of this modules. The map file can be a Verilog source file (*.v) or an ilang file (*.il). -map <map_file> use the modules in this file as reference. This option can be used multiple times. -map %<design-name> use the modules in this in-memory design as reference. This option can be used multiple times. -verbose print debug output while analyzing -constports also find instances with constant drivers. this may be much slower than the normal operation. -nodefaultswaps normally builtin port swapping rules for internal cells are used per default. This turns that off, so e.g. 'a^b' does not match 'b^a' when this option is used. -compat <needle_type> <haystack_type> Per default, the cells in the map file (needle) must have the type as the cells in the active design (haystack). This option can be used to register additional pairs of types that should match. This option can be used multiple times. -swap <needle_type> <port1>,<port2>[,...] Register a set of swappable ports for a needle cell type. This option can be used multiple times. -perm <needle_type> <port1>,<port2>[,...] <portA>,<portB>[,...] Register a valid permutation of swappable ports for a needle cell type. This option can be used multiple times. -cell_attr <attribute_name> Attributes on cells with the given name must match. -wire_attr <attribute_name> Attributes on wires with the given name must match. -ignore_parameters Do not use parameters when matching cells. -ignore_param <cell_type> <parameter_name> Do not use this parameter when matching cells. This pass does not operate on modules with unprocessed processes in it. (I.e. the 'proc' pass should be used first to convert processes to netlists.) This pass can also be used for mining for frequent subcircuits. In this mode the following options are to be used instead of the -map option. -mine <out_file> mine for frequent subcircuits and write them to the given ilang file -mine_cells_span <min> <max> only mine for subcircuits with the specified number of cells default value: 3 5 -mine_min_freq <num> only mine for subcircuits with at least the specified number of matches default value: 10 -mine_limit_matches_per_module <num> when calculating the number of matches for a subcircuit, don't count more than the specified number of matches per module -mine_max_fanout <num> don't consider internal signals with more than <num> connections The modules in the map file may have the attribute 'extract_order' set to an integer value. Then this value is used to determine the order in which the pass tries to map the modules to the design (ascending, default value is 0). See 'help techmap' for a pass that does the opposite thing. \end{lstlisting} \section{extract\_counter -- Extract GreenPak4 counter cells} \label{cmd:extract_counter} \begin{lstlisting}[numbers=left,frame=single] extract_counter [options] [selection] This pass converts non-resettable or async resettable down counters to counter cells. Use a target-specific 'techmap' map file to convert those cells to the actual target cells. -maxwidth N Only extract counters up to N bits wide -pout X,Y,... Only allow parallel output from the counter to the listed cell types (if not specified, parallel outputs are not restricted) \end{lstlisting} \section{extract\_fa -- find and extract full/half adders} \label{cmd:extract_fa} \begin{lstlisting}[numbers=left,frame=single] extract_fa [options] [selection] This pass extracts full/half adders from a gate-level design. -fa, -ha Enable cell types (fa=full adder, ha=half adder) All types are enabled if none of this options is used -d <int> Set maximum depth for extracted logic cones (default=20) -b <int> Set maximum breadth for extracted logic cones (default=6) -v Verbose output \end{lstlisting} \section{extract\_reduce -- converts gate chains into \$reduce\_* cells} \label{cmd:extract_reduce} \begin{lstlisting}[numbers=left,frame=single] extract_reduce [options] [selection] converts gate chains into $reduce_* cells This command finds chains of $_AND_, $_OR_, and $_XOR_ cells and replaces them with their corresponding $reduce_* cells. Because this command only operates on these cell types, it is recommended to map the design to only these cell types using the `abc -g` command. Note that, in some cases, it may be more effective to map the design to only $_AND_ cells, run extract_reduce, map the remaining parts of the design to AND/OR/XOR cells, and run extract_reduce a second time. -allow-off-chain Allows matching of cells that have loads outside the chain. These cells will be replicated and folded into the $reduce_* cell, but the original cell will remain, driving its original loads. \end{lstlisting} \section{flatten -- flatten design} \label{cmd:flatten} \begin{lstlisting}[numbers=left,frame=single] flatten [selection] This pass flattens the design by replacing cells by their implementation. This pass is very similar to the 'techmap' pass. The only difference is that this pass is using the current design as mapping library. Cells and/or modules with the 'keep_hierarchy' attribute set will not be flattened by this command. \end{lstlisting} \section{freduce -- perform functional reduction} \label{cmd:freduce} \begin{lstlisting}[numbers=left,frame=single] freduce [options] [selection] This pass performs functional reduction in the circuit. I.e. if two nodes are equivalent, they are merged to one node and one of the redundant drivers is disconnected. A subsequent call to 'clean' will remove the redundant drivers. -v, -vv enable verbose or very verbose output -inv enable explicit handling of inverted signals -stop <n> stop after <n> reduction operations. this is mostly used for debugging the freduce command itself. -dump <prefix> dump the design to <prefix>_<module>_<num>.il after each reduction operation. this is mostly used for debugging the freduce command. This pass is undef-aware, i.e. it considers don't-care values for detecting equivalent nodes. All selected wires are considered for rewiring. The selected cells cover the circuit that is analyzed. \end{lstlisting} \section{fsm -- extract and optimize finite state machines} \label{cmd:fsm} \begin{lstlisting}[numbers=left,frame=single] fsm [options] [selection] This pass calls all the other fsm_* passes in a useful order. This performs FSM extraction and optimization. It also calls opt_clean as needed: fsm_detect unless got option -nodetect fsm_extract fsm_opt opt_clean fsm_opt fsm_expand if got option -expand opt_clean if got option -expand fsm_opt if got option -expand fsm_recode unless got option -norecode fsm_info fsm_export if got option -export fsm_map unless got option -nomap Options: -expand, -norecode, -export, -nomap enable or disable passes as indicated above -fullexpand call expand with -full option -encoding type -fm_set_fsm_file file -encfile file passed through to fsm_recode pass \end{lstlisting} \section{fsm\_detect -- finding FSMs in design} \label{cmd:fsm_detect} \begin{lstlisting}[numbers=left,frame=single] fsm_detect [selection] This pass detects finite state machines by identifying the state signal. The state signal is then marked by setting the attribute 'fsm_encoding' on the state signal to "auto". Existing 'fsm_encoding' attributes are not changed by this pass. Signals can be protected from being detected by this pass by setting the 'fsm_encoding' attribute to "none". \end{lstlisting} \section{fsm\_expand -- expand FSM cells by merging logic into it} \label{cmd:fsm_expand} \begin{lstlisting}[numbers=left,frame=single] fsm_expand [-full] [selection] The fsm_extract pass is conservative about the cells that belong to a finite state machine. This pass can be used to merge additional auxiliary gates into the finite state machine. By default, fsm_expand is still a bit conservative regarding merging larger word-wide cells. Call with -full to consider all cells for merging. \end{lstlisting} \section{fsm\_export -- exporting FSMs to KISS2 files} \label{cmd:fsm_export} \begin{lstlisting}[numbers=left,frame=single] fsm_export [-noauto] [-o filename] [-origenc] [selection] This pass creates a KISS2 file for every selected FSM. For FSMs with the 'fsm_export' attribute set, the attribute value is used as filename, otherwise the module and cell name is used as filename. If the parameter '-o' is given, the first exported FSM is written to the specified filename. This overwrites the setting as specified with the 'fsm_export' attribute. All other FSMs are exported to the default name as mentioned above. -noauto only export FSMs that have the 'fsm_export' attribute set -o filename filename of the first exported FSM -origenc use binary state encoding as state names instead of s0, s1, ... \end{lstlisting} \section{fsm\_extract -- extracting FSMs in design} \label{cmd:fsm_extract} \begin{lstlisting}[numbers=left,frame=single] fsm_extract [selection] This pass operates on all signals marked as FSM state signals using the 'fsm_encoding' attribute. It consumes the logic that creates the state signal and uses the state signal to generate control signal and replaces it with an FSM cell. The generated FSM cell still generates the original state signal with its original encoding. The 'fsm_opt' pass can be used in combination with the 'opt_clean' pass to eliminate this signal. \end{lstlisting} \section{fsm\_info -- print information on finite state machines} \label{cmd:fsm_info} \begin{lstlisting}[numbers=left,frame=single] fsm_info [selection] This pass dumps all internal information on FSM cells. It can be useful for analyzing the synthesis process and is called automatically by the 'fsm' pass so that this information is included in the synthesis log file. \end{lstlisting} \section{fsm\_map -- mapping FSMs to basic logic} \label{cmd:fsm_map} \begin{lstlisting}[numbers=left,frame=single] fsm_map [selection] This pass translates FSM cells to flip-flops and logic. \end{lstlisting} \section{fsm\_opt -- optimize finite state machines} \label{cmd:fsm_opt} \begin{lstlisting}[numbers=left,frame=single] fsm_opt [selection] This pass optimizes FSM cells. It detects which output signals are actually not used and removes them from the FSM. This pass is usually used in combination with the 'opt_clean' pass (see also 'help fsm'). \end{lstlisting} \section{fsm\_recode -- recoding finite state machines} \label{cmd:fsm_recode} \begin{lstlisting}[numbers=left,frame=single] fsm_recode [options] [selection] This pass reassign the state encodings for FSM cells. At the moment only one-hot encoding and binary encoding is supported. -encoding <type> specify the encoding scheme used for FSMs without the 'fsm_encoding' attribute or with the attribute set to `auto'. -fm_set_fsm_file <file> generate a file containing the mapping from old to new FSM encoding in form of Synopsys Formality set_fsm_* commands. -encfile <file> write the mappings from old to new FSM encoding to a file in the following format: .fsm <module_name> <state_signal> .map <old_bitpattern> <new_bitpattern> \end{lstlisting} \section{greenpak4\_dffinv -- merge greenpak4 inverters and DFF/latches} \label{cmd:greenpak4_dffinv} \begin{lstlisting}[numbers=left,frame=single] greenpak4_dffinv [options] [selection] Merge GP_INV cells with GP_DFF* and GP_DLATCH* cells. \end{lstlisting} \section{help -- display help messages} \label{cmd:help} \begin{lstlisting}[numbers=left,frame=single] help ................ list all commands help <command> ...... print help message for given command help -all ........... print complete command reference help -cells .......... list all cell types help <celltype> ..... print help message for given cell type help <celltype>+ .... print verilog code for given cell type \end{lstlisting} \section{hierarchy -- check, expand and clean up design hierarchy} \label{cmd:hierarchy} \begin{lstlisting}[numbers=left,frame=single] hierarchy [-check] [-top <module>] hierarchy -generate <cell-types> <port-decls> In parametric designs, a module might exists in several variations with different parameter values. This pass looks at all modules in the current design an re-runs the language frontends for the parametric modules as needed. -check also check the design hierarchy. this generates an error when an unknown module is used as cell type. -simcheck like -check, but also thow an error if blackbox modules are instantiated, and throw an error if the design has no top module -purge_lib by default the hierarchy command will not remove library (blackbox) modules. use this option to also remove unused blackbox modules. -libdir <directory> search for files named <module_name>.v in the specified directory for unknown modules and automatically run read_verilog for each unknown module. -keep_positionals per default this pass also converts positional arguments in cells to arguments using port names. this option disables this behavior. -keep_portwidths per default this pass adjusts the port width on cells that are module instances when the width does not match the module port. this option disables this behavior. -nokeep_asserts per default this pass sets the "keep" attribute on all modules that directly or indirectly contain one or more $assert cells. this option disables this behavior. -top <module> use the specified top module to built a design hierarchy. modules outside this tree (unused modules) are removed. when the -top option is used, the 'top' attribute will be set on the specified top module. otherwise a module with the 'top' attribute set will implicitly be used as top module, if such a module exists. -auto-top automatically determine the top of the design hierarchy and mark it. In -generate mode this pass generates blackbox modules for the given cell types (wildcards supported). For this the design is searched for cells that match the given types and then the given port declarations are used to determine the direction of the ports. The syntax for a port declaration is: {i|o|io}[@<num>]:<portname> Input ports are specified with the 'i' prefix, output ports with the 'o' prefix and inout ports with the 'io' prefix. The optional <num> specifies the position of the port in the parameter list (needed when instantiated using positional arguments). When <num> is not specified, the <portname> can also contain wildcard characters. This pass ignores the current selection and always operates on all modules in the current design. \end{lstlisting} \section{hilomap -- technology mapping of constant hi- and/or lo-drivers} \label{cmd:hilomap} \begin{lstlisting}[numbers=left,frame=single] hilomap [options] [selection] Map constants to 'tielo' and 'tiehi' driver cells. -hicell <celltype> <portname> Replace constant hi bits with this cell. -locell <celltype> <portname> Replace constant lo bits with this cell. -singleton Create only one hi/lo cell and connect all constant bits to that cell. Per default a separate cell is created for each constant bit. \end{lstlisting} \section{history -- show last interactive commands} \label{cmd:history} \begin{lstlisting}[numbers=left,frame=single] history This command prints all commands in the shell history buffer. This are all commands executed in an interactive session, but not the commands from executed scripts. \end{lstlisting} \section{ice40\_ffinit -- iCE40: handle FF init values} \label{cmd:ice40_ffinit} \begin{lstlisting}[numbers=left,frame=single] ice40_ffinit [options] [selection] Remove zero init values for FF output signals. Add inverters to implement nonzero init values. \end{lstlisting} \section{ice40\_ffssr -- iCE40: merge synchronous set/reset into FF cells} \label{cmd:ice40_ffssr} \begin{lstlisting}[numbers=left,frame=single] ice40_ffssr [options] [selection] Merge synchronous set/reset $_MUX_ cells into iCE40 FFs. \end{lstlisting} \section{ice40\_opt -- iCE40: perform simple optimizations} \label{cmd:ice40_opt} \begin{lstlisting}[numbers=left,frame=single] ice40_opt [options] [selection] This command executes the following script: do <ice40 specific optimizations> opt_expr -mux_undef -undriven [-full] opt_merge opt_rmdff opt_clean while <changed design> When called with the option -unlut, this command will transform all already mapped SB_LUT4 cells back to logic. \end{lstlisting} \section{insbuf -- insert buffer cells for connected wires} \label{cmd:insbuf} \begin{lstlisting}[numbers=left,frame=single] insbuf [options] [selection] Insert buffer cells into the design for directly connected wires. -buf <celltype> <in-portname> <out-portname> Use the given cell type instead of $_BUF_. (Notice that the next call to "clean" will remove all $_BUF_ in the design.) \end{lstlisting} \section{iopadmap -- technology mapping of i/o pads (or buffers)} \label{cmd:iopadmap} \begin{lstlisting}[numbers=left,frame=single] iopadmap [options] [selection] Map module inputs/outputs to PAD cells from a library. This pass can only map to very simple PAD cells. Use 'techmap' to further map the resulting cells to more sophisticated PAD cells. -inpad <celltype> <portname>[:<portname>] Map module input ports to the given cell type with the given output port name. if a 2nd portname is given, the signal is passed through the pad call, using the 2nd portname as the port facing the module port. -outpad <celltype> <portname>[:<portname>] -inoutpad <celltype> <portname>[:<portname>] Similar to -inpad, but for output and inout ports. -toutpad <celltype> <portname>:<portname>[:<portname>] Merges $_TBUF_ cells into the output pad cell. This takes precedence over the other -outpad cell. The first portname is the enable input of the tristate driver. -tinoutpad <celltype> <portname>:<portname>:<portname>[:<portname>] Merges $_TBUF_ cells into the inout pad cell. This takes precedence over the other -inoutpad cell. The first portname is the enable input of the tristate driver and the 2nd portname is the internal output buffering the external signal. -widthparam <param_name> Use the specified parameter name to set the port width. -nameparam <param_name> Use the specified parameter to set the port name. -bits create individual bit-wide buffers even for ports that are wider. (the default behavior is to create word-wide buffers using -widthparam to set the word size on the cell.) Tristate PADS (-toutpad, -tinoutpad) always operate in -bits mode. \end{lstlisting} \section{json -- write design in JSON format} \label{cmd:json} \begin{lstlisting}[numbers=left,frame=single] json [options] [selection] Write a JSON netlist of all selected objects. -o <filename> write to the specified file. -aig also include AIG models for the different gate types See 'help write_json' for a description of the JSON format used. \end{lstlisting} \section{log -- print text and log files} \label{cmd:log} \begin{lstlisting}[numbers=left,frame=single] log string Print the given string to the screen and/or the log file. This is useful for TCL scripts, because the TCL command "puts" only goes to stdout but not to logfiles. -stdout Print the output to stdout too. This is useful when all Yosys is executed with a script and the -q (quiet operation) argument to notify the user. -stderr Print the output to stderr too. -nolog Don't use the internal log() command. Use either -stdout or -stderr, otherwise no output will be generated at all. -n do not append a newline \end{lstlisting} \section{ls -- list modules or objects in modules} \label{cmd:ls} \begin{lstlisting}[numbers=left,frame=single] ls [selection] When no active module is selected, this prints a list of modules. When an active module is selected, this prints a list of objects in the module. \end{lstlisting} \section{ltp -- print longest topological path} \label{cmd:ltp} \begin{lstlisting}[numbers=left,frame=single] ltp [options] [selection] This command prints the longest topological path in the design. (Only considers paths within a single module, so the design must be flattened.) -noff automatically exclude FF cell types \end{lstlisting} \section{lut2mux -- convert \$lut to \$\_MUX\_} \label{cmd:lut2mux} \begin{lstlisting}[numbers=left,frame=single] lut2mux [options] [selection] This pass converts $lut cells to $_MUX_ gates. \end{lstlisting} \section{maccmap -- mapping macc cells} \label{cmd:maccmap} \begin{lstlisting}[numbers=left,frame=single] maccmap [-unmap] [selection] This pass maps $macc cells to yosys $fa and $alu cells. When the -unmap option is used then the $macc cell is mapped to $add, $sub, etc. cells instead. \end{lstlisting} \section{memory -- translate memories to basic cells} \label{cmd:memory} \begin{lstlisting}[numbers=left,frame=single] memory [-nomap] [-nordff] [-memx] [-bram <bram_rules>] [selection] This pass calls all the other memory_* passes in a useful order: memory_dff [-nordff] (-memx implies -nordff) opt_clean memory_share opt_clean memory_memx (when called with -memx) memory_collect memory_bram -rules <bram_rules> (when called with -bram) memory_map (skipped if called with -nomap) This converts memories to word-wide DFFs and address decoders or multiport memory blocks if called with the -nomap option. \end{lstlisting} \section{memory\_bram -- map memories to block rams} \label{cmd:memory_bram} \begin{lstlisting}[numbers=left,frame=single] memory_bram -rules <rule_file> [selection] This pass converts the multi-port $mem memory cells into block ram instances. The given rules file describes the available resources and how they should be used. The rules file contains a set of block ram description and a sequence of match rules. A block ram description looks like this: bram RAMB1024X32 # name of BRAM cell init 1 # set to '1' if BRAM can be initialized abits 10 # number of address bits dbits 32 # number of data bits groups 2 # number of port groups ports 1 1 # number of ports in each group wrmode 1 0 # set to '1' if this groups is write ports enable 4 1 # number of enable bits transp 0 2 # transparent (for read ports) clocks 1 2 # clock configuration clkpol 2 2 # clock polarity configuration endbram For the option 'transp' the value 0 means non-transparent, 1 means transparent and a value greater than 1 means configurable. All groups with the same value greater than 1 share the same configuration bit. For the option 'clocks' the value 0 means non-clocked, and a value greater than 0 means clocked. All groups with the same value share the same clock signal. For the option 'clkpol' the value 0 means negative edge, 1 means positive edge and a value greater than 1 means configurable. All groups with the same value greater than 1 share the same configuration bit. Using the same bram name in different bram blocks will create different variants of the bram. Verilog configuration parameters for the bram are created as needed. It is also possible to create variants by repeating statements in the bram block and appending '@<label>' to the individual statements. A match rule looks like this: match RAMB1024X32 max waste 16384 # only use this bram if <= 16k ram bits are unused min efficiency 80 # only use this bram if efficiency is at least 80% endmatch It is possible to match against the following values with min/max rules: words ........ number of words in memory in design abits ........ number of address bits on memory in design dbits ........ number of data bits on memory in design wports ....... number of write ports on memory in design rports ....... number of read ports on memory in design ports ........ number of ports on memory in design bits ......... number of bits in memory in design dups .......... number of duplications for more read ports awaste ....... number of unused address slots for this match dwaste ....... number of unused data bits for this match bwaste ....... number of unused bram bits for this match waste ........ total number of unused bram bits (bwaste*dups) efficiency ... total percentage of used and non-duplicated bits acells ....... number of cells in 'address-direction' dcells ....... number of cells in 'data-direction' cells ........ total number of cells (acells*dcells*dups) The interface for the created bram instances is derived from the bram description. Use 'techmap' to convert the created bram instances into instances of the actual bram cells of your target architecture. A match containing the command 'or_next_if_better' is only used if it has a higher efficiency than the next match (and the one after that if the next also has 'or_next_if_better' set, and so forth). A match containing the command 'make_transp' will add external circuitry to simulate 'transparent read', if necessary. A match containing the command 'make_outreg' will add external flip-flops to implement synchronous read ports, if necessary. A match containing the command 'shuffle_enable A' will re-organize the data bits to accommodate the enable pattern of port A. \end{lstlisting} \section{memory\_collect -- creating multi-port memory cells} \label{cmd:memory_collect} \begin{lstlisting}[numbers=left,frame=single] memory_collect [selection] This pass collects memories and memory ports and creates generic multiport memory cells. \end{lstlisting} \section{memory\_dff -- merge input/output DFFs into memories} \label{cmd:memory_dff} \begin{lstlisting}[numbers=left,frame=single] memory_dff [options] [selection] This pass detects DFFs at memory ports and merges them into the memory port. I.e. it consumes an asynchronous memory port and the flip-flops at its interface and yields a synchronous memory port. -nordfff do not merge registers on read ports \end{lstlisting} \section{memory\_map -- translate multiport memories to basic cells} \label{cmd:memory_map} \begin{lstlisting}[numbers=left,frame=single] memory_map [selection] This pass converts multiport memory cells as generated by the memory_collect pass to word-wide DFFs and address decoders. \end{lstlisting} \section{memory\_memx -- emulate vlog sim behavior for mem ports} \label{cmd:memory_memx} \begin{lstlisting}[numbers=left,frame=single] memory_memx [selection] This pass adds additional circuitry that emulates the Verilog simulation behavior for out-of-bounds memory reads and writes. \end{lstlisting} \section{memory\_nordff -- extract read port FFs from memories} \label{cmd:memory_nordff} \begin{lstlisting}[numbers=left,frame=single] memory_nordff [options] [selection] This pass extracts FFs from memory read ports. This results in a netlist similar to what one would get from calling memory_dff with -nordff. \end{lstlisting} \section{memory\_share -- consolidate memory ports} \label{cmd:memory_share} \begin{lstlisting}[numbers=left,frame=single] memory_share [selection] This pass merges share-able memory ports into single memory ports. The following methods are used to consolidate the number of memory ports: - When write ports are connected to async read ports accessing the same address, then this feedback path is converted to a write port with byte/part enable signals. - When multiple write ports access the same address then this is converted to a single write port with a more complex data and/or enable logic path. - When multiple write ports are never accessed at the same time (a SAT solver is used to determine this), then the ports are merged into a single write port. Note that in addition to the algorithms implemented in this pass, the $memrd and $memwr cells are also subject to generic resource sharing passes (and other optimizations) such as "share" and "opt_merge". \end{lstlisting} \section{memory\_unpack -- unpack multi-port memory cells} \label{cmd:memory_unpack} \begin{lstlisting}[numbers=left,frame=single] memory_unpack [selection] This pass converts the multi-port $mem memory cells into individual $memrd and $memwr cells. It is the counterpart to the memory_collect pass. \end{lstlisting} \section{miter -- automatically create a miter circuit} \label{cmd:miter} \begin{lstlisting}[numbers=left,frame=single] miter -equiv [options] gold_name gate_name miter_name Creates a miter circuit for equivalence checking. The gold- and gate- modules must have the same interfaces. The miter circuit will have all inputs of the two source modules, prefixed with 'in_'. The miter circuit has a 'trigger' output that goes high if an output mismatch between the two source modules is detected. -ignore_gold_x a undef (x) bit in the gold module output will match any value in the gate module output. -make_outputs also route the gold- and gate-outputs to 'gold_*' and 'gate_*' outputs on the miter circuit. -make_outcmp also create a cmp_* output for each gold/gate output pair. -make_assert also create an 'assert' cell that checks if trigger is always low. -flatten call 'flatten; opt_expr -keepdc -undriven;;' on the miter circuit. miter -assert [options] module [miter_name] Creates a miter circuit for property checking. All input ports are kept, output ports are discarded. An additional output 'trigger' is created that goes high when an assert is violated. Without a miter_name, the existing module is modified. -make_outputs keep module output ports. -flatten call 'flatten; opt_expr -keepdc -undriven;;' on the miter circuit. \end{lstlisting} \section{muxcover -- cover trees of MUX cells with wider MUXes} \label{cmd:muxcover} \begin{lstlisting}[numbers=left,frame=single] muxcover [options] [selection] Cover trees of $_MUX_ cells with $_MUX{4,8,16}_ cells -mux4, -mux8, -mux16 Use the specified types of MUXes. If none of those options are used, the effect is the same as if all of them where used. -nodecode Do not insert decoder logic. This reduces the number of possible substitutions, but guarantees that the resulting circuit is not less efficient than the original circuit. \end{lstlisting} \section{nlutmap -- map to LUTs of different sizes} \label{cmd:nlutmap} \begin{lstlisting}[numbers=left,frame=single] nlutmap [options] [selection] This pass uses successive calls to 'abc' to map to an architecture. That provides a small number of differently sized LUTs. -luts N_1,N_2,N_3,... The number of LUTs with 1, 2, 3, ... inputs that are available in the target architecture. -assert Create an error if not all logic can be mapped Excess logic that does not fit into the specified LUTs is mapped back to generic logic gates ($_AND_, etc.). \end{lstlisting} \section{opt -- perform simple optimizations} \label{cmd:opt} \begin{lstlisting}[numbers=left,frame=single] opt [options] [selection] This pass calls all the other opt_* passes in a useful order. This performs a series of trivial optimizations and cleanups. This pass executes the other passes in the following order: opt_expr [-mux_undef] [-mux_bool] [-undriven] [-clkinv] [-fine] [-full] [-keepdc] opt_merge [-share_all] -nomux do opt_muxtree opt_reduce [-fine] [-full] opt_merge [-share_all] opt_rmdff [-keepdc] opt_clean [-purge] opt_expr [-mux_undef] [-mux_bool] [-undriven] [-clkinv] [-fine] [-full] [-keepdc] while <changed design> When called with -fast the following script is used instead: do opt_expr [-mux_undef] [-mux_bool] [-undriven] [-clkinv] [-fine] [-full] [-keepdc] opt_merge [-share_all] opt_rmdff [-keepdc] opt_clean [-purge] while <changed design in opt_rmdff> Note: Options in square brackets (such as [-keepdc]) are passed through to the opt_* commands when given to 'opt'. \end{lstlisting} \section{opt\_clean -- remove unused cells and wires} \label{cmd:opt_clean} \begin{lstlisting}[numbers=left,frame=single] opt_clean [options] [selection] This pass identifies wires and cells that are unused and removes them. Other passes often remove cells but leave the wires in the design or reconnect the wires but leave the old cells in the design. This pass can be used to clean up after the passes that do the actual work. This pass only operates on completely selected modules without processes. -purge also remove internal nets if they have a public name \end{lstlisting} \section{opt\_demorgan -- Optimize reductions with DeMorgan equivalents} \label{cmd:opt_demorgan} \begin{lstlisting}[numbers=left,frame=single] opt_demorgan [selection] This pass pushes inverters through $reduce_* cells if this will reduce the overall gate count of the circuit \end{lstlisting} \section{opt\_expr -- perform const folding and simple expression rewriting} \label{cmd:opt_expr} \begin{lstlisting}[numbers=left,frame=single] opt_expr [options] [selection] This pass performs const folding on internal cell types with constant inputs. It also performs some simple expression rewritring. -mux_undef remove 'undef' inputs from $mux, $pmux and $_MUX_ cells -mux_bool replace $mux cells with inverters or buffers when possible -undriven replace undriven nets with undef (x) constants -clkinv optimize clock inverters by changing FF types -fine perform fine-grain optimizations -full alias for -mux_undef -mux_bool -undriven -fine -keepdc some optimizations change the behavior of the circuit with respect to don't-care bits. for example in 'a+0' a single x-bit in 'a' will cause all result bits to be set to x. this behavior changes when 'a+0' is replaced by 'a'. the -keepdc option disables all such optimizations. \end{lstlisting} \section{opt\_merge -- consolidate identical cells} \label{cmd:opt_merge} \begin{lstlisting}[numbers=left,frame=single] opt_merge [options] [selection] This pass identifies cells with identical type and input signals. Such cells are then merged to one cell. -nomux Do not merge MUX cells. -share_all Operate on all cell types, not just built-in types. \end{lstlisting} \section{opt\_muxtree -- eliminate dead trees in multiplexer trees} \label{cmd:opt_muxtree} \begin{lstlisting}[numbers=left,frame=single] opt_muxtree [selection] This pass analyzes the control signals for the multiplexer trees in the design and identifies inputs that can never be active. It then removes this dead branches from the multiplexer trees. This pass only operates on completely selected modules without processes. \end{lstlisting} \section{opt\_reduce -- simplify large MUXes and AND/OR gates} \label{cmd:opt_reduce} \begin{lstlisting}[numbers=left,frame=single] opt_reduce [options] [selection] This pass performs two interlinked optimizations: 1. it consolidates trees of large AND gates or OR gates and eliminates duplicated inputs. 2. it identifies duplicated inputs to MUXes and replaces them with a single input with the original control signals OR'ed together. -fine perform fine-grain optimizations -full alias for -fine \end{lstlisting} \section{opt\_rmdff -- remove DFFs with constant inputs} \label{cmd:opt_rmdff} \begin{lstlisting}[numbers=left,frame=single] opt_rmdff [-keepdc] [selection] This pass identifies flip-flops with constant inputs and replaces them with a constant driver. \end{lstlisting} \section{plugin -- load and list loaded plugins} \label{cmd:plugin} \begin{lstlisting}[numbers=left,frame=single] plugin [options] Load and list loaded plugins. -i <plugin_filename> Load (install) the specified plugin. -a <alias_name> Register the specified alias name for the loaded plugin -l List loaded plugins \end{lstlisting} \section{pmuxtree -- transform \$pmux cells to trees of \$mux cells} \label{cmd:pmuxtree} \begin{lstlisting}[numbers=left,frame=single] pmuxtree [options] [selection] This pass transforms $pmux cells to a trees of $mux cells. \end{lstlisting} \section{prep -- generic synthesis script} \label{cmd:prep} \begin{lstlisting}[numbers=left,frame=single] prep [options] This command runs a conservative RTL synthesis. A typical application for this is the preparation stage of a verification flow. This command does not operate on partly selected designs. -top <module> use the specified module as top module (default='top') -auto-top automatically determine the top of the design hierarchy -flatten flatten the design before synthesis. this will pass '-auto-top' to 'hierarchy' if no top module is specified. -ifx passed to 'proc'. uses verilog simulation behavior for verilog if/case undef handling. this also prevents 'wreduce' from being run. -memx simulate verilog simulation behavior for out-of-bounds memory accesses using the 'memory_memx' pass. -nomem do not run any of the memory_* passes -rdff do not pass -nordff to 'memory_dff'. This enables merging of FFs into memory read ports. -nokeepdc do not call opt_* with -keepdc -run <from_label>[:<to_label>] only run the commands between the labels (see below). an empty from label is synonymous to 'begin', and empty to label is synonymous to the end of the command list. The following commands are executed by this synthesis command: begin: hierarchy -check [-top <top> | -auto-top] coarse: proc [-ifx] flatten (if -flatten) opt_expr -keepdc opt_clean check opt -keepdc wreduce [-memx] memory_dff [-nordff] memory_memx (if -memx) opt_clean memory_collect opt -keepdc -fast check: stat check \end{lstlisting} \section{proc -- translate processes to netlists} \label{cmd:proc} \begin{lstlisting}[numbers=left,frame=single] proc [options] [selection] This pass calls all the other proc_* passes in the most common order. proc_clean proc_rmdead proc_init proc_arst proc_mux proc_dlatch proc_dff proc_clean This replaces the processes in the design with multiplexers, flip-flops and latches. The following options are supported: -global_arst [!]<netname> This option is passed through to proc_arst. -ifx This option is passed through to proc_mux. proc_rmdead is not executed in -ifx mode. \end{lstlisting} \section{proc\_arst -- detect asynchronous resets} \label{cmd:proc_arst} \begin{lstlisting}[numbers=left,frame=single] proc_arst [-global_arst [!]<netname>] [selection] This pass identifies asynchronous resets in the processes and converts them to a different internal representation that is suitable for generating flip-flop cells with asynchronous resets. -global_arst [!]<netname> In modules that have a net with the given name, use this net as async reset for registers that have been assign initial values in their declaration ('reg foobar = constant_value;'). Use the '!' modifier for active low reset signals. Note: the frontend stores the default value in the 'init' attribute on the net. \end{lstlisting} \section{proc\_clean -- remove empty parts of processes} \label{cmd:proc_clean} \begin{lstlisting}[numbers=left,frame=single] proc_clean [selection] This pass removes empty parts of processes and ultimately removes a process if it contains only empty structures. \end{lstlisting} \section{proc\_dff -- extract flip-flops from processes} \label{cmd:proc_dff} \begin{lstlisting}[numbers=left,frame=single] proc_dff [selection] This pass identifies flip-flops in the processes and converts them to d-type flip-flop cells. \end{lstlisting} \section{proc\_dlatch -- extract latches from processes} \label{cmd:proc_dlatch} \begin{lstlisting}[numbers=left,frame=single] proc_dlatch [selection] This pass identifies latches in the processes and converts them to d-type latches. \end{lstlisting} \section{proc\_init -- convert initial block to init attributes} \label{cmd:proc_init} \begin{lstlisting}[numbers=left,frame=single] proc_init [selection] This pass extracts the 'init' actions from processes (generated from Verilog 'initial' blocks) and sets the initial value to the 'init' attribute on the respective wire. \end{lstlisting} \section{proc\_mux -- convert decision trees to multiplexers} \label{cmd:proc_mux} \begin{lstlisting}[numbers=left,frame=single] proc_mux [options] [selection] This pass converts the decision trees in processes (originating from if-else and case statements) to trees of multiplexer cells. -ifx Use Verilog simulation behavior with respect to undef values in 'case' expressions and 'if' conditions. \end{lstlisting} \section{proc\_rmdead -- eliminate dead trees in decision trees} \label{cmd:proc_rmdead} \begin{lstlisting}[numbers=left,frame=single] proc_rmdead [selection] This pass identifies unreachable branches in decision trees and removes them. \end{lstlisting} \section{qwp -- quadratic wirelength placer} \label{cmd:qwp} \begin{lstlisting}[numbers=left,frame=single] qwp [options] [selection] This command runs quadratic wirelength placement on the selected modules and annotates the cells in the design with 'qwp_position' attributes. -ltr Add left-to-right constraints: constrain all inputs on the left border outputs to the right border. -alpha Add constraints for inputs/outputs to be placed in alphanumerical order along the y-axis (top-to-bottom). -grid N Number of grid divisions in x- and y-direction. (default=16) -dump <html_file_name> Dump a protocol of the placement algorithm to the html file. -v Verbose solver output for profiling or debugging Note: This implementation of a quadratic wirelength placer uses exact dense matrix operations. It is only a toy-placer for small circuits. \end{lstlisting} \section{read -- load HDL designs} \label{cmd:read} \begin{lstlisting}[numbers=left,frame=single] read {-vlog95|-vlog2k|-sv2005|-sv2009|-sv2012|-sv|-formal} <verilog-file>.. Load the specified Verilog/SystemVerilog files. (Full SystemVerilog support is only available via Verific.) Additional -D<macro>[=<value>] options may be added after the option indicating the language version (and before file names) to set additional verilog defines. read {-vhdl87|-vhdl93|-vhdl2k|-vhdl2008|-vhdl} <vhdl-file>.. Load the specified VHDL files. (Requires Verific.) read -define <macro>[=<value>].. Set global Verilog/SystemVerilog defines. read -undef <macro>.. Unset global Verilog/SystemVerilog defines. read -incdir <directory> Add directory to global Verilog/SystemVerilog include directories. \end{lstlisting} \section{read\_blif -- read BLIF file} \label{cmd:read_blif} \begin{lstlisting}[numbers=left,frame=single] read_blif [filename] Load modules from a BLIF file into the current design. -sop Create $sop cells instead of $lut cells -wideports Merge ports that match the pattern 'name[int]' into a single multi-bit port 'name'. \end{lstlisting} \section{read\_ilang -- read modules from ilang file} \label{cmd:read_ilang} \begin{lstlisting}[numbers=left,frame=single] read_ilang [filename] Load modules from an ilang file to the current design. (ilang is a text representation of a design in yosys's internal format.) \end{lstlisting} \section{read\_json -- read JSON file} \label{cmd:read_json} \begin{lstlisting}[numbers=left,frame=single] read_json [filename] Load modules from a JSON file into the current design See "help write_json" for a description of the file format. \end{lstlisting} \section{read\_liberty -- read cells from liberty file} \label{cmd:read_liberty} \begin{lstlisting}[numbers=left,frame=single] read_liberty [filename] Read cells from liberty file as modules into current design. -lib only create empty blackbox modules -nooverwrite ignore re-definitions of modules. (the default behavior is to create an error message if the existing module is not a blackbox module, and overwrite the existing module if it is a blackbox module.) -overwrite overwrite existing modules with the same name -ignore_miss_func ignore cells with missing function specification of outputs -ignore_miss_dir ignore cells with a missing or invalid direction specification on a pin -ignore_miss_data_latch ignore latches with missing data and/or enable pins -setattr <attribute_name> set the specified attribute (to the value 1) on all loaded modules \end{lstlisting} \section{read\_verilog -- read modules from Verilog file} \label{cmd:read_verilog} \begin{lstlisting}[numbers=left,frame=single] read_verilog [options] [filename] Load modules from a Verilog file to the current design. A large subset of Verilog-2005 is supported. -sv enable support for SystemVerilog features. (only a small subset of SystemVerilog is supported) -formal enable support for SystemVerilog assertions and some Yosys extensions replace the implicit -D SYNTHESIS with -D FORMAL -norestrict ignore restrict() assertions -assume-asserts treat all assert() statements like assume() statements -dump_ast1 dump abstract syntax tree (before simplification) -dump_ast2 dump abstract syntax tree (after simplification) -no_dump_ptr do not include hex memory addresses in dump (easier to diff dumps) -dump_vlog dump ast as Verilog code (after simplification) -dump_rtlil dump generated RTLIL netlist -yydebug enable parser debug output -nolatches usually latches are synthesized into logic loops this option prohibits this and sets the output to 'x' in what would be the latches hold condition this behavior can also be achieved by setting the 'nolatches' attribute on the respective module or always block. -nomem2reg under certain conditions memories are converted to registers early during simplification to ensure correct handling of complex corner cases. this option disables this behavior. this can also be achieved by setting the 'nomem2reg' attribute on the respective module or register. This is potentially dangerous. Usually the front-end has good reasons for converting an array to a list of registers. Prohibiting this step will likely result in incorrect synthesis results. -mem2reg always convert memories to registers. this can also be achieved by setting the 'mem2reg' attribute on the respective module or register. -nomeminit do not infer $meminit cells and instead convert initialized memories to registers directly in the front-end. -ppdump dump Verilog code after pre-processor -nopp do not run the pre-processor -nodpi disable DPI-C support -lib only create empty blackbox modules. This implies -DBLACKBOX. -noopt don't perform basic optimizations (such as const folding) in the high-level front-end. -icells interpret cell types starting with '$' as internal cell types -nooverwrite ignore re-definitions of modules. (the default behavior is to create an error message if the existing module is not a black box module, and overwrite the existing module otherwise.) -overwrite overwrite existing modules with the same name -defer only read the abstract syntax tree and defer actual compilation to a later 'hierarchy' command. Useful in cases where the default parameters of modules yield invalid or not synthesizable code. -noautowire make the default of `default_nettype be "none" instead of "wire". -setattr <attribute_name> set the specified attribute (to the value 1) on all loaded modules -Dname[=definition] define the preprocessor symbol 'name' and set its optional value 'definition' -Idir add 'dir' to the directories which are used when searching include files The command 'verilog_defaults' can be used to register default options for subsequent calls to 'read_verilog'. Note that the Verilog frontend does a pretty good job of processing valid verilog input, but has not very good error reporting. It generally is recommended to use a simulator (for example Icarus Verilog) for checking the syntax of the code, rather than to rely on read_verilog for that. Depending on if read_verilog is run in -formal mode, either the macro SYNTHESIS or FORMAL is defined automatically. In addition, read_verilog always defines the macro YOSYS. See the Yosys README file for a list of non-standard Verilog features supported by the Yosys Verilog front-end. \end{lstlisting} \section{rename -- rename object in the design} \label{cmd:rename} \begin{lstlisting}[numbers=left,frame=single] rename old_name new_name Rename the specified object. Note that selection patterns are not supported by this command. rename -enumerate [-pattern <pattern>] [selection] Assign short auto-generated names to all selected wires and cells with private names. The -pattern option can be used to set the pattern for the new names. The character % in the pattern is replaced with a integer number. The default pattern is '_%_'. rename -hide [selection] Assign private names (the ones with $-prefix) to all selected wires and cells with public names. This ignores all selected ports. rename -top new_name Rename top module. \end{lstlisting} \section{rmports -- remove module ports with no connections} \label{cmd:rmports} \begin{lstlisting}[numbers=left,frame=single] rmports [selection] This pass identifies ports in the selected modules which are not used or driven and removes them. \end{lstlisting} \section{sat -- solve a SAT problem in the circuit} \label{cmd:sat} \begin{lstlisting}[numbers=left,frame=single] sat [options] [selection] This command solves a SAT problem defined over the currently selected circuit and additional constraints passed as parameters. -all show all solutions to the problem (this can grow exponentially, use -max <N> instead to get <N> solutions) -max <N> like -all, but limit number of solutions to <N> -enable_undef enable modeling of undef value (aka 'x-bits') this option is implied by -set-def, -set-undef et. cetera -max_undef maximize the number of undef bits in solutions, giving a better picture of which input bits are actually vital to the solution. -set <signal> <value> set the specified signal to the specified value. -set-def <signal> add a constraint that all bits of the given signal must be defined -set-any-undef <signal> add a constraint that at least one bit of the given signal is undefined -set-all-undef <signal> add a constraint that all bits of the given signal are undefined -set-def-inputs add -set-def constraints for all module inputs -show <signal> show the model for the specified signal. if no -show option is passed then a set of signals to be shown is automatically selected. -show-inputs, -show-outputs, -show-ports add all module (input/output) ports to the list of shown signals -show-regs, -show-public, -show-all show all registers, show signals with 'public' names, show all signals -ignore_div_by_zero ignore all solutions that involve a division by zero -ignore_unknown_cells ignore all cells that can not be matched to a SAT model The following options can be used to set up a sequential problem: -seq <N> set up a sequential problem with <N> time steps. The steps will be numbered from 1 to N. note: for large <N> it can be significantly faster to use -tempinduct-baseonly -maxsteps <N> instead of -seq <N>. -set-at <N> <signal> <value> -unset-at <N> <signal> set or unset the specified signal to the specified value in the given timestep. this has priority over a -set for the same signal. -set-assumes set all assumptions provided via $assume cells -set-def-at <N> <signal> -set-any-undef-at <N> <signal> -set-all-undef-at <N> <signal> add undef constraints in the given timestep. -set-init <signal> <value> set the initial value for the register driving the signal to the value -set-init-undef set all initial states (not set using -set-init) to undef -set-init-def do not force a value for the initial state but do not allow undef -set-init-zero set all initial states (not set using -set-init) to zero -dump_vcd <vcd-file-name> dump SAT model (counter example in proof) to VCD file -dump_json <json-file-name> dump SAT model (counter example in proof) to a WaveJSON file. -dump_cnf <cnf-file-name> dump CNF of SAT problem (in DIMACS format). in temporal induction proofs this is the CNF of the first induction step. The following additional options can be used to set up a proof. If also -seq is passed, a temporal induction proof is performed. -tempinduct Perform a temporal induction proof. In a temporal induction proof it is proven that the condition holds forever after the number of time steps specified using -seq. -tempinduct-def Perform a temporal induction proof. Assume an initial state with all registers set to defined values for the induction step. -tempinduct-baseonly Run only the basecase half of temporal induction (requires -maxsteps) -tempinduct-inductonly Run only the induction half of temporal induction -tempinduct-skip <N> Skip the first <N> steps of the induction proof. note: this will assume that the base case holds for <N> steps. this must be proven independently with "-tempinduct-baseonly -maxsteps <N>". Use -initsteps if you just want to set a minimal induction length. -prove <signal> <value> Attempt to proof that <signal> is always <value>. -prove-x <signal> <value> Like -prove, but an undef (x) bit in the lhs matches any value on the right hand side. Useful for equivalence checking. -prove-asserts Prove that all asserts in the design hold. -prove-skip <N> Do not enforce the prove-condition for the first <N> time steps. -maxsteps <N> Set a maximum length for the induction. -initsteps <N> Set initial length for the induction. This will speed up the search of the right induction length for deep induction proofs. -stepsize <N> Increase the size of the induction proof in steps of <N>. This will speed up the search of the right induction length for deep induction proofs. -timeout <N> Maximum number of seconds a single SAT instance may take. -verify Return an error and stop the synthesis script if the proof fails. -verify-no-timeout Like -verify but do not return an error for timeouts. -falsify Return an error and stop the synthesis script if the proof succeeds. -falsify-no-timeout Like -falsify but do not return an error for timeouts. \end{lstlisting} \section{scatter -- add additional intermediate nets} \label{cmd:scatter} \begin{lstlisting}[numbers=left,frame=single] scatter [selection] This command adds additional intermediate nets on all cell ports. This is used for testing the correct use of the SigMap helper in passes. If you don't know what this means: don't worry -- you only need this pass when testing your own extensions to Yosys. Use the opt_clean command to get rid of the additional nets. \end{lstlisting} \section{scc -- detect strongly connected components (logic loops)} \label{cmd:scc} \begin{lstlisting}[numbers=left,frame=single] scc [options] [selection] This command identifies strongly connected components (aka logic loops) in the design. -expect <num> expect to find exactly <num> SSCs. A different number of SSCs will produce an error. -max_depth <num> limit to loops not longer than the specified number of cells. This can e.g. be useful in identifying small local loops in a module that implements one large SCC. -nofeedback do not count cells that have their output fed back into one of their inputs as single-cell scc. -all_cell_types Usually this command only considers internal non-memory cells. With this option set, all cells are considered. For unknown cells all ports are assumed to be bidirectional 'inout' ports. -set_attr <name> <value> set the specified attribute on all cells that are part of a logic loop. the special token {} in the value is replaced with a unique identifier for the logic loop. -select replace the current selection with a selection of all cells and wires that are part of a found logic loop \end{lstlisting} \section{script -- execute commands from script file} \label{cmd:script} \begin{lstlisting}[numbers=left,frame=single] script <filename> [<from_label>:<to_label>] This command executes the yosys commands in the specified file. The 2nd argument can be used to only execute the section of the file between the specified labels. An empty from label is synonymous for the beginning of the file and an empty to label is synonymous for the end of the file. If only one label is specified (without ':') then only the block marked with that label (until the next label) is executed. \end{lstlisting} \section{select -- modify and view the list of selected objects} \label{cmd:select} \begin{lstlisting}[numbers=left,frame=single] select [ -add | -del | -set <name> ] {-read <filename> | <selection>} select [ <assert_option> ] {-read <filename> | <selection>} select [ -list | -write <filename> | -count | -clear ] select -module <modname> Most commands use the list of currently selected objects to determine which part of the design to operate on. This command can be used to modify and view this list of selected objects. Note that many commands support an optional [selection] argument that can be used to YS_OVERRIDE the global selection for the command. The syntax of this optional argument is identical to the syntax of the <selection> argument described here. -add, -del add or remove the given objects to the current selection. without this options the current selection is replaced. -set <name> do not modify the current selection. instead save the new selection under the given name (see @<name> below). to save the current selection, use "select -set <name> %" -assert-none do not modify the current selection. instead assert that the given selection is empty. i.e. produce an error if any object matching the selection is found. -assert-any do not modify the current selection. instead assert that the given selection is non-empty. i.e. produce an error if no object matching the selection is found. -assert-count N do not modify the current selection. instead assert that the given selection contains exactly N objects. -assert-max N do not modify the current selection. instead assert that the given selection contains less than or exactly N objects. -assert-min N do not modify the current selection. instead assert that the given selection contains at least N objects. -list list all objects in the current selection -write <filename> like -list but write the output to the specified file -read <filename> read the specified file (written by -write) -count count all objects in the current selection -clear clear the current selection. this effectively selects the whole design. it also resets the selected module (see -module). use the command 'select *' to select everything but stay in the current module. -none create an empty selection. the current module is unchanged. -module <modname> limit the current scope to the specified module. the difference between this and simply selecting the module is that all object names are interpreted relative to this module after this command until the selection is cleared again. When this command is called without an argument, the current selection is displayed in a compact form (i.e. only the module name when a whole module is selected). The <selection> argument itself is a series of commands for a simple stack machine. Each element on the stack represents a set of selected objects. After this commands have been executed, the union of all remaining sets on the stack is computed and used as selection for the command. Pushing (selecting) object when not in -module mode: <mod_pattern> select the specified module(s) <mod_pattern>/<obj_pattern> select the specified object(s) from the module(s) Pushing (selecting) object when in -module mode: <obj_pattern> select the specified object(s) from the current module A <mod_pattern> can be a module name, wildcard expression (*, ?, [..]) matching module names, or one of the following: A:<pattern>, A:<pattern>=<pattern> all modules with an attribute matching the given pattern in addition to = also <, <=, >=, and > are supported An <obj_pattern> can be an object name, wildcard expression, or one of the following: w:<pattern> all wires with a name matching the given wildcard pattern i:<pattern>, o:<pattern>, x:<pattern> all inputs (i:), outputs (o:) or any ports (x:) with matching names s:<size>, s:<min>:<max> all wires with a matching width m:<pattern> all memories with a name matching the given pattern c:<pattern> all cells with a name matching the given pattern t:<pattern> all cells with a type matching the given pattern p:<pattern> all processes with a name matching the given pattern a:<pattern> all objects with an attribute name matching the given pattern a:<pattern>=<pattern> all objects with a matching attribute name-value-pair. in addition to = also <, <=, >=, and > are supported r:<pattern>, r:<pattern>=<pattern> cells with matching parameters. also with <, <=, >= and >. n:<pattern> all objects with a name matching the given pattern (i.e. 'n:' is optional as it is the default matching rule) @<name> push the selection saved prior with 'select -set <name> ...' The following actions can be performed on the top sets on the stack: % push a copy of the current selection to the stack %% replace the stack with a union of all elements on it %n replace top set with its invert %u replace the two top sets on the stack with their union %i replace the two top sets on the stack with their intersection %d pop the top set from the stack and subtract it from the new top %D like %d but swap the roles of two top sets on the stack %c create a copy of the top set from the stack and push it %x[<num1>|*][.<num2>][:<rule>[:<rule>..]] expand top set <num1> num times according to the specified rules. (i.e. select all cells connected to selected wires and select all wires connected to selected cells) The rules specify which cell ports to use for this. the syntax for a rule is a '-' for exclusion and a '+' for inclusion, followed by an optional comma separated list of cell types followed by an optional comma separated list of cell ports in square brackets. a rule can also be just a cell or wire name that limits the expansion (is included but does not go beyond). select at most <num2> objects. a warning message is printed when this limit is reached. When '*' is used instead of <num1> then the process is repeated until no further object are selected. %ci[<num1>|*][.<num2>][:<rule>[:<rule>..]] %co[<num1>|*][.<num2>][:<rule>[:<rule>..]] similar to %x, but only select input (%ci) or output cones (%co) %xe[...] %cie[...] %coe like %x, %ci, and %co but only consider combinatorial cells %a expand top set by selecting all wires that are (at least in part) aliases for selected wires. %s expand top set by adding all modules that implement cells in selected modules %m expand top set by selecting all modules that contain selected objects %M select modules that implement selected cells %C select cells that implement selected modules %R[<num>] select <num> random objects from top selection (default 1) Example: the following command selects all wires that are connected to a 'GATE' input of a 'SWITCH' cell: select */t:SWITCH %x:+[GATE] */t:SWITCH %d \end{lstlisting} \section{setattr -- set/unset attributes on objects} \label{cmd:setattr} \begin{lstlisting}[numbers=left,frame=single] setattr [ -mod ] [ -set name value | -unset name ]... [selection] Set/unset the given attributes on the selected objects. String values must be passed in double quotes ("). When called with -mod, this command will set and unset attributes on modules instead of objects within modules. \end{lstlisting} \section{setparam -- set/unset parameters on objects} \label{cmd:setparam} \begin{lstlisting}[numbers=left,frame=single] setparam [ -type cell_type ] [ -set name value | -unset name ]... [selection] Set/unset the given parameters on the selected cells. String values must be passed in double quotes ("). The -type option can be used to change the cell type of the selected cells. \end{lstlisting} \section{setundef -- replace undef values with defined constants} \label{cmd:setundef} \begin{lstlisting}[numbers=left,frame=single] setundef [options] [selection] This command replaces undef (x) constants with defined (0/1) constants. -undriven also set undriven nets to constant values -expose also expose undriven nets as inputs (use with -undriven) -zero replace with bits cleared (0) -one replace with bits set (1) -undef replace with undef (x) bits, may be used with -undriven -anyseq replace with $anyseq drivers (for formal) -anyconst replace with $anyconst drivers (for formal) -random <seed> replace with random bits using the specified integer als seed value for the random number generator. -init also create/update init values for flip-flops \end{lstlisting} \section{share -- perform sat-based resource sharing} \label{cmd:share} \begin{lstlisting}[numbers=left,frame=single] share [options] [selection] This pass merges shareable resources into a single resource. A SAT solver is used to determine if two resources are share-able. -force Per default the selection of cells that is considered for sharing is narrowed using a list of cell types. With this option all selected cells are considered for resource sharing. IMPORTANT NOTE: If the -all option is used then no cells with internal state must be selected! -aggressive Per default some heuristics are used to reduce the number of cells considered for resource sharing to only large resources. This options turns this heuristics off, resulting in much more cells being considered for resource sharing. -fast Only consider the simple part of the control logic in SAT solving, resulting in much easier SAT problems at the cost of maybe missing some opportunities for resource sharing. -limit N Only perform the first N merges, then stop. This is useful for debugging. \end{lstlisting} \section{shell -- enter interactive command mode} \label{cmd:shell} \begin{lstlisting}[numbers=left,frame=single] shell This command enters the interactive command mode. This can be useful in a script to interrupt the script at a certain point and allow for interactive inspection or manual synthesis of the design at this point. The command prompt of the interactive shell indicates the current selection (see 'help select'): yosys> the entire design is selected yosys*> only part of the design is selected yosys [modname]> the entire module 'modname' is selected using 'select -module modname' yosys [modname]*> only part of current module 'modname' is selected When in interactive shell, some errors (e.g. invalid command arguments) do not terminate yosys but return to the command prompt. This command is the default action if nothing else has been specified on the command line. Press Ctrl-D or type 'exit' to leave the interactive shell. \end{lstlisting} \section{show -- generate schematics using graphviz} \label{cmd:show} \begin{lstlisting}[numbers=left,frame=single] show [options] [selection] Create a graphviz DOT file for the selected part of the design and compile it to a graphics file (usually SVG or PostScript). -viewer <viewer> Run the specified command with the graphics file as parameter. On Windows, this pauses yosys until the viewer exits. -format <format> Generate a graphics file in the specified format. Use 'dot' to just generate a .dot file, or other <format> strings such as 'svg' or 'ps' to generate files in other formats (this calls the 'dot' command). -lib <verilog_or_ilang_file> Use the specified library file for determining whether cell ports are inputs or outputs. This option can be used multiple times to specify more than one library. note: in most cases it is better to load the library before calling show with 'read_verilog -lib <filename>'. it is also possible to load liberty files with 'read_liberty -lib <filename>'. -prefix <prefix> generate <prefix>.* instead of ~/.yosys_show.* -color <color> <object> assign the specified color to the specified object. The object can be a single selection wildcard expressions or a saved set of objects in the @<name> syntax (see "help select" for details). -label <text> <object> assign the specified label text to the specified object. The object can be a single selection wildcard expressions or a saved set of objects in the @<name> syntax (see "help select" for details). -colors <seed> Randomly assign colors to the wires. The integer argument is the seed for the random number generator. Change the seed value if the colored graph still is ambiguous. A seed of zero deactivates the coloring. -colorattr <attribute_name> Use the specified attribute to assign colors. A unique color is assigned to each unique value of this attribute. -width annotate busses with a label indicating the width of the bus. -signed mark ports (A, B) that are declared as signed (using the [AB]_SIGNED cell parameter) with an asterisk next to the port name. -stretch stretch the graph so all inputs are on the left side and all outputs (including inout ports) are on the right side. -pause wait for the use to press enter to before returning -enum enumerate objects with internal ($-prefixed) names -long do not abbreviate objects with internal ($-prefixed) names -notitle do not add the module name as graph title to the dot file When no <format> is specified, 'dot' is used. When no <format> and <viewer> is specified, 'xdot' is used to display the schematic (POSIX systems only). The generated output files are '~/.yosys_show.dot' and '~/.yosys_show.<format>', unless another prefix is specified using -prefix <prefix>. Yosys on Windows and YosysJS use different defaults: The output is written to 'show.dot' in the current directory and new viewer is launched each time the 'show' command is executed. \end{lstlisting} \section{shregmap -- map shift registers} \label{cmd:shregmap} \begin{lstlisting}[numbers=left,frame=single] shregmap [options] [selection] This pass converts chains of $_DFF_[NP]_ gates to target specific shift register primitives. The generated shift register will be of type $__SHREG_DFF_[NP]_ and will use the same interface as the original $_DFF_*_ cells. The cell parameter 'DEPTH' will contain the depth of the shift register. Use a target-specific 'techmap' map file to convert those cells to the actual target cells. -minlen N minimum length of shift register (default = 2) (this is the length after -keep_before and -keep_after) -maxlen N maximum length of shift register (default = no limit) larger chains will be mapped to multiple shift register instances -keep_before N number of DFFs to keep before the shift register (default = 0) -keep_after N number of DFFs to keep after the shift register (default = 0) -clkpol pos|neg|any limit match to only positive or negative edge clocks. (default = any) -enpol pos|neg|none|any_or_none|any limit match to FFs with the specified enable polarity. (default = none) -match <cell_type>[:<d_port_name>:<q_port_name>] match the specified cells instead of $_DFF_N_ and $_DFF_P_. If ':<d_port_name>:<q_port_name>' is omitted then 'D' and 'Q' is used by default. E.g. the option '-clkpol pos' is just an alias for '-match $_DFF_P_', which is an alias for '-match $_DFF_P_:D:Q'. -params instead of encoding the clock and enable polarity in the cell name by deriving from the original cell name, simply name all generated cells $__SHREG_ and use CLKPOL and ENPOL parameters. An ENPOL value of 2 is used to denote cells without enable input. The ENPOL parameter is omitted when '-enpol none' (or no -enpol option) is passed. -zinit assume the shift register is automatically zero-initialized, so it becomes legal to merge zero initialized FFs into the shift register. -init map initialized registers to the shift reg, add an INIT parameter to generated cells with the initialization value. (first bit to shift out in LSB position) -tech greenpak4 map to greenpak4 shift registers. \end{lstlisting} \section{sim -- simulate the circuit} \label{cmd:sim} \begin{lstlisting}[numbers=left,frame=single] sim [options] [top-level] This command simulates the circuit using the given top-level module. -vcd <filename> write the simulation results to the given VCD file -clock <portname> name of top-level clock input -clockn <portname> name of top-level clock input (inverse polarity) -reset <portname> name of top-level reset input (active high) -resetn <portname> name of top-level inverted reset input (active low) -rstlen <integer> number of cycles reset should stay active (default: 1) -zinit zero-initialize all uninitialized regs and memories -n <integer> number of cycles to simulate (default: 20) -a include all nets in VCD output, not just those with public names -w writeback mode: use final simulation state as new init state -d enable debug output \end{lstlisting} \section{simplemap -- mapping simple coarse-grain cells} \label{cmd:simplemap} \begin{lstlisting}[numbers=left,frame=single] simplemap [selection] This pass maps a small selection of simple coarse-grain cells to yosys gate primitives. The following internal cell types are mapped by this pass: $not, $pos, $and, $or, $xor, $xnor $reduce_and, $reduce_or, $reduce_xor, $reduce_xnor, $reduce_bool $logic_not, $logic_and, $logic_or, $mux, $tribuf $sr, $ff, $dff, $dffsr, $adff, $dlatch \end{lstlisting} \section{splice -- create explicit splicing cells} \label{cmd:splice} \begin{lstlisting}[numbers=left,frame=single] splice [options] [selection] This command adds $slice and $concat cells to the design to make the splicing of multi-bit signals explicit. This for example is useful for coarse grain synthesis, where dedicated hardware is needed to splice signals. -sel_by_cell only select the cell ports to rewire by the cell. if the selection contains a cell, than all cell inputs are rewired, if necessary. -sel_by_wire only select the cell ports to rewire by the wire. if the selection contains a wire, than all cell ports driven by this wire are wired, if necessary. -sel_any_bit it is sufficient if the driver of any bit of a cell port is selected. by default all bits must be selected. -wires also add $slice and $concat cells to drive otherwise unused wires. -no_outputs do not rewire selected module outputs. -port <name> only rewire cell ports with the specified name. can be used multiple times. implies -no_output. -no_port <name> do not rewire cell ports with the specified name. can be used multiple times. can not be combined with -port <name>. By default selected output wires and all cell ports of selected cells driven by selected wires are rewired. \end{lstlisting} \section{splitnets -- split up multi-bit nets} \label{cmd:splitnets} \begin{lstlisting}[numbers=left,frame=single] splitnets [options] [selection] This command splits multi-bit nets into single-bit nets. -format char1[char2[char3]] the first char is inserted between the net name and the bit index, the second char is appended to the netname. e.g. -format () creates net names like 'mysignal(42)'. the 3rd character is the range separation character when creating multi-bit wires. the default is '[]:'. -ports also split module ports. per default only internal signals are split. -driver don't blindly split nets in individual bits. instead look at the driver and split nets so that no driver drives only part of a net. \end{lstlisting} \section{stat -- print some statistics} \label{cmd:stat} \begin{lstlisting}[numbers=left,frame=single] stat [options] [selection] Print some statistics (number of objects) on the selected portion of the design. -top <module> print design hierarchy with this module as top. if the design is fully selected and a module has the 'top' attribute set, this module is used default value for this option. -liberty <liberty_file> use cell area information from the provided liberty file -width annotate internal cell types with their word width. e.g. $add_8 for an 8 bit wide $add cell. \end{lstlisting} \section{submod -- moving part of a module to a new submodule} \label{cmd:submod} \begin{lstlisting}[numbers=left,frame=single] submod [-copy] [selection] This pass identifies all cells with the 'submod' attribute and moves them to a newly created module. The value of the attribute is used as name for the cell that replaces the group of cells with the same attribute value. This pass can be used to create a design hierarchy in flat design. This can be useful for analyzing or reverse-engineering a design. This pass only operates on completely selected modules with no processes or memories. submod -name <name> [-copy] [selection] As above, but don't use the 'submod' attribute but instead use the selection. Only objects from one module might be selected. The value of the -name option is used as the value of the 'submod' attribute above. By default the cells are 'moved' from the source module and the source module will use an instance of the new module after this command is finished. Call with -copy to not modify the source module. \end{lstlisting} \section{synth -- generic synthesis script} \label{cmd:synth} \begin{lstlisting}[numbers=left,frame=single] synth [options] This command runs the default synthesis script. This command does not operate on partly selected designs. -top <module> use the specified module as top module (default='top') -auto-top automatically determine the top of the design hierarchy -flatten flatten the design before synthesis. this will pass '-auto-top' to 'hierarchy' if no top module is specified. -encfile <file> passed to 'fsm_recode' via 'fsm' -nofsm do not run FSM optimization -noabc do not run abc (as if yosys was compiled without ABC support) -noalumacc do not run 'alumacc' pass. i.e. keep arithmetic operators in their direct form ($add, $sub, etc.). -nordff passed to 'memory'. prohibits merging of FFs into memory read ports -noshare do not run SAT-based resource sharing -run <from_label>[:<to_label>] only run the commands between the labels (see below). an empty from label is synonymous to 'begin', and empty to label is synonymous to the end of the command list. The following commands are executed by this synthesis command: begin: hierarchy -check [-top <top> | -auto-top] coarse: proc flatten (if -flatten) opt_expr opt_clean check opt wreduce alumacc share opt fsm opt -fast memory -nomap opt_clean fine: opt -fast -full memory_map opt -full techmap opt -fast abc -fast opt -fast check: hierarchy -check stat check \end{lstlisting} \section{synth\_achronix -- synthesis for Acrhonix Speedster22i FPGAs.} \label{cmd:synth_achronix} \begin{lstlisting}[numbers=left,frame=single] synth_achronix [options] This command runs synthesis for Achronix Speedster eFPGAs. This work is still experimental. -top <module> use the specified module as top module (default='top') -vout <file> write the design to the specified Verilog netlist file. writing of an output file is omitted if this parameter is not specified. -run <from_label>:<to_label> only run the commands between the labels (see below). an empty from label is synonymous to 'begin', and empty to label is synonymous to the end of the command list. -noflatten do not flatten design before synthesis -retime run 'abc' with -dff option The following commands are executed by this synthesis command: begin: read_verilog -sv -lib +/achronix/speedster22i/cells_sim.v hierarchy -check -top <top> flatten: (unless -noflatten) proc flatten tribuf -logic deminout coarse: synth -run coarse fine: opt -fast -mux_undef -undriven -fine -full memory_map opt -undriven -fine dffsr2dff dff2dffe -direct-match $_DFF_* opt -fine techmap -map +/techmap.v opt -full clean -purge setundef -undriven -zero abc -markgroups -dff (only if -retime) map_luts: abc -lut 4 clean map_cells: iopadmap -bits -outpad $__outpad I:O -inpad $__inpad O:I techmap -map +/achronix/speedster22i/cells_map.v clean -purge check: hierarchy -check stat check -noinit vout: write_verilog -nodec -attr2comment -defparam -renameprefix syn_ <file-name> \end{lstlisting} \section{synth\_coolrunner2 -- synthesis for Xilinx Coolrunner-II CPLDs} \label{cmd:synth_coolrunner2} \begin{lstlisting}[numbers=left,frame=single] synth_coolrunner2 [options] This command runs synthesis for Coolrunner-II CPLDs. This work is experimental. It is intended to be used with https://github.com/azonenberg/openfpga as the place-and-route. -top <module> use the specified module as top module (default='top') -json <file> write the design to the specified JSON file. writing of an output file is omitted if this parameter is not specified. -run <from_label>:<to_label> only run the commands between the labels (see below). an empty from label is synonymous to 'begin', and empty to label is synonymous to the end of the command list. -noflatten do not flatten design before synthesis -retime run 'abc' with -dff option The following commands are executed by this synthesis command: begin: read_verilog -lib +/coolrunner2/cells_sim.v hierarchy -check -top <top> flatten: (unless -noflatten) proc flatten tribuf -logic coarse: synth -run coarse fine: opt -fast -full techmap techmap -map +/coolrunner2/cells_latch.v dfflibmap -prepare -liberty +/coolrunner2/xc2_dff.lib map_tff: abc -g AND,XOR clean extract -map +/coolrunner2/tff_extract.v map_pla: abc -sop -I 40 -P 56 clean map_cells: dfflibmap -liberty +/coolrunner2/xc2_dff.lib dffinit -ff FDCP Q INIT dffinit -ff FDCP_N Q INIT dffinit -ff FTCP Q INIT dffinit -ff FTCP_N Q INIT dffinit -ff LDCP Q INIT dffinit -ff LDCP_N Q INIT coolrunner2_sop iopadmap -bits -inpad IBUF O:I -outpad IOBUFE I:IO -inoutpad IOBUFE O:IO -toutpad IOBUFE E:I:IO -tinoutpad IOBUFE E:O:I:IO attrmvcp -attr src -attr LOC t:IOBUFE n:* attrmvcp -attr src -attr LOC -driven t:IBUF n:* splitnets clean check: hierarchy -check stat check -noinit json: write_json <file-name> \end{lstlisting} \section{synth\_easic -- synthesis for eASIC platform} \label{cmd:synth_easic} \begin{lstlisting}[numbers=left,frame=single] synth_easic [options] This command runs synthesis for eASIC platform. -top <module> use the specified module as top module -vlog <file> write the design to the specified structural Verilog file. writing of an output file is omitted if this parameter is not specified. -etools <path> set path to the eTools installation. (default=/opt/eTools) -run <from_label>:<to_label> only run the commands between the labels (see below). an empty from label is synonymous to 'begin', and empty to label is synonymous to the end of the command list. -noflatten do not flatten design before synthesis -retime run 'abc' with -dff option The following commands are executed by this synthesis command: begin: read_liberty -lib <etools_phys_clk_lib> read_liberty -lib <etools_logic_lut_lib> hierarchy -check -top <top> flatten: (unless -noflatten) proc flatten coarse: synth -run coarse fine: opt -fast -mux_undef -undriven -fine memory_map opt -undriven -fine techmap opt -fast abc -dff (only if -retime) opt_clean (only if -retime) map: dfflibmap -liberty <etools_phys_clk_lib> abc -liberty <etools_logic_lut_lib> opt_clean check: hierarchy -check stat check -noinit vlog: write_verilog -noexpr -attr2comment <file-name> \end{lstlisting} \section{synth\_ecp5 -- synthesis for ECP5 FPGAs} \label{cmd:synth_ecp5} \begin{lstlisting}[numbers=left,frame=single] synth_ecp5 [options] This command runs synthesis for ECP5 FPGAs. -top <module> use the specified module as top module -blif <file> write the design to the specified BLIF file. writing of an output file is omitted if this parameter is not specified. -edif <file> write the design to the specified EDIF file. writing of an output file is omitted if this parameter is not specified. -json <file> write the design to the specified JSON file. writing of an output file is omitted if this parameter is not specified. -run <from_label>:<to_label> only run the commands between the labels (see below). an empty from label is synonymous to 'begin', and empty to label is synonymous to the end of the command list. -noflatten do not flatten design before synthesis -retime run 'abc' with -dff option -noccu2 do not use CCU2 cells in output netlist -nodffe do not use flipflops with CE in output netlist -nobram do not use BRAM cells in output netlist -nodram do not use distributed RAM cells in output netlist -nomux do not use PFU muxes to implement LUTs larger than LUT4s -abc2 run two passes of 'abc' for slightly improved logic density -vpr generate an output netlist (and BLIF file) suitable for VPR (this feature is experimental and incomplete) The following commands are executed by this synthesis command: begin: read_verilog -lib +/ecp5/cells_sim.v hierarchy -check -top <top> flatten: (unless -noflatten) proc flatten tribuf -logic deminout coarse: synth -run coarse bram: (skip if -nobram) dram: (skip if -nodram) memory_bram -rules +/ecp5/dram.txt techmap -map +/ecp5/drams_map.v fine: opt -fast -mux_undef -undriven -fine memory_map opt -undriven -fine techmap -map +/techmap.v -map +/ecp5/arith_map.v abc -dff (only if -retime) map_ffs: dffsr2dff dff2dffs opt_clean dff2dffe -direct-match $_DFF_* -direct-match $__DFFS_* techmap -D NO_LUT -map +/ecp5/cells_map.v opt_expr -mux_undef simplemap map_luts: abc (only if -abc2) abc -lut 4:7 clean map_cells: techmap -map +/ecp5/cells_map.v (with -D NO_LUT in vpr mode) clean check: hierarchy -check stat check -noinit blif: opt_clean -purge (vpr mode) write_blif -attr -cname -conn -param <file-name> (vpr mode) write_blif -gates -attr -param <file-name> (non-vpr mode) edif: write_edif <file-name> json: write_json <file-name> \end{lstlisting} \section{synth\_gowin -- synthesis for Gowin FPGAs} \label{cmd:synth_gowin} \begin{lstlisting}[numbers=left,frame=single] synth_gowin [options] This command runs synthesis for Gowin FPGAs. This work is experimental. -top <module> use the specified module as top module (default='top') -vout <file> write the design to the specified Verilog netlist file. writing of an output file is omitted if this parameter is not specified. -run <from_label>:<to_label> only run the commands between the labels (see below). an empty from label is synonymous to 'begin', and empty to label is synonymous to the end of the command list. -retime run 'abc' with -dff option The following commands are executed by this synthesis command: begin: read_verilog -lib +/gowin/cells_sim.v hierarchy -check -top <top> flatten: proc flatten tribuf -logic deminout coarse: synth -run coarse fine: opt -fast -mux_undef -undriven -fine memory_map opt -undriven -fine techmap clean -purge splitnets -ports setundef -undriven -zero abc -dff (only if -retime) map_luts: abc -lut 4 clean map_cells: techmap -map +/gowin/cells_map.v hilomap -hicell VCC V -locell GND G iopadmap -inpad IBUF O:I -outpad OBUF I:O clean -purge check: hierarchy -check stat check -noinit vout: write_verilog -nodec -attr2comment -defparam -renameprefix gen <file-name> \end{lstlisting} \section{synth\_greenpak4 -- synthesis for GreenPAK4 FPGAs} \label{cmd:synth_greenpak4} \begin{lstlisting}[numbers=left,frame=single] synth_greenpak4 [options] This command runs synthesis for GreenPAK4 FPGAs. This work is experimental. It is intended to be used with https://github.com/azonenberg/openfpga as the place-and-route. -top <module> use the specified module as top module (default='top') -part <part> synthesize for the specified part. Valid values are SLG46140V, SLG46620V, and SLG46621V (default). -json <file> write the design to the specified JSON file. writing of an output file is omitted if this parameter is not specified. -run <from_label>:<to_label> only run the commands between the labels (see below). an empty from label is synonymous to 'begin', and empty to label is synonymous to the end of the command list. -noflatten do not flatten design before synthesis -retime run 'abc' with -dff option The following commands are executed by this synthesis command: begin: read_verilog -lib +/greenpak4/cells_sim.v hierarchy -check -top <top> flatten: (unless -noflatten) proc flatten tribuf -logic coarse: synth -run coarse fine: extract_counter -pout GP_DCMP,GP_DAC -maxwidth 14 clean opt -fast -mux_undef -undriven -fine memory_map opt -undriven -fine techmap techmap -map +/greenpak4/cells_latch.v dfflibmap -prepare -liberty +/greenpak4/gp_dff.lib opt -fast abc -dff (only if -retime) map_luts: nlutmap -assert -luts 0,6,8,2 (for -part SLG46140V) nlutmap -assert -luts 2,8,16,2 (for -part SLG46620V) nlutmap -assert -luts 2,8,16,2 (for -part SLG46621V) clean map_cells: shregmap -tech greenpak4 dfflibmap -liberty +/greenpak4/gp_dff.lib dffinit -ff GP_DFF Q INIT dffinit -ff GP_DFFR Q INIT dffinit -ff GP_DFFS Q INIT dffinit -ff GP_DFFSR Q INIT iopadmap -bits -inpad GP_IBUF OUT:IN -outpad GP_OBUF IN:OUT -inoutpad GP_OBUF OUT:IN -toutpad GP_OBUFT OE:IN:OUT -tinoutpad GP_IOBUF OE:OUT:IN:IO attrmvcp -attr src -attr LOC t:GP_OBUF t:GP_OBUFT t:GP_IOBUF n:* attrmvcp -attr src -attr LOC -driven t:GP_IBUF n:* techmap -map +/greenpak4/cells_map.v greenpak4_dffinv clean check: hierarchy -check stat check -noinit json: write_json <file-name> \end{lstlisting} \section{synth\_ice40 -- synthesis for iCE40 FPGAs} \label{cmd:synth_ice40} \begin{lstlisting}[numbers=left,frame=single] synth_ice40 [options] This command runs synthesis for iCE40 FPGAs. -top <module> use the specified module as top module -blif <file> write the design to the specified BLIF file. writing of an output file is omitted if this parameter is not specified. -edif <file> write the design to the specified EDIF file. writing of an output file is omitted if this parameter is not specified. -json <file> write the design to the specified JSON file. writing of an output file is omitted if this parameter is not specified. -run <from_label>:<to_label> only run the commands between the labels (see below). an empty from label is synonymous to 'begin', and empty to label is synonymous to the end of the command list. -noflatten do not flatten design before synthesis -retime run 'abc' with -dff option -nocarry do not use SB_CARRY cells in output netlist -nodffe do not use SB_DFFE* cells in output netlist -nobram do not use SB_RAM40_4K* cells in output netlist -abc2 run two passes of 'abc' for slightly improved logic density -vpr generate an output netlist (and BLIF file) suitable for VPR (this feature is experimental and incomplete) The following commands are executed by this synthesis command: begin: read_verilog -lib +/ice40/cells_sim.v hierarchy -check -top <top> flatten: (unless -noflatten) proc flatten tribuf -logic deminout coarse: synth -run coarse bram: (skip if -nobram) memory_bram -rules +/ice40/brams.txt techmap -map +/ice40/brams_map.v fine: opt -fast -mux_undef -undriven -fine memory_map opt -undriven -fine techmap -map +/techmap.v -map +/ice40/arith_map.v abc -dff (only if -retime) ice40_opt map_ffs: dffsr2dff dff2dffe -direct-match $_DFF_* techmap -D NO_LUT -map +/ice40/cells_map.v opt_expr -mux_undef simplemap ice40_ffinit ice40_ffssr ice40_opt -full map_luts: abc (only if -abc2) ice40_opt (only if -abc2) techmap -map +/ice40/latches_map.v abc -lut 4 clean map_cells: techmap -map +/ice40/cells_map.v (with -D NO_LUT in vpr mode) clean check: hierarchy -check stat check -noinit blif: opt_clean -purge (vpr mode) write_blif -attr -cname -conn -param <file-name> (vpr mode) write_blif -gates -attr -param <file-name> (non-vpr mode) edif: write_edif <file-name> json: write_json <file-name> \end{lstlisting} \section{synth\_intel -- synthesis for Intel (Altera) FPGAs.} \label{cmd:synth_intel} \begin{lstlisting}[numbers=left,frame=single] synth_intel [options] This command runs synthesis for Intel FPGAs. -family < max10 | a10gx | cyclone10 | cyclonev | cycloneiv | cycloneive> generate the synthesis netlist for the specified family. MAX10 is the default target if not family argument specified. For Cyclone GX devices, use cycloneiv argument; For Cyclone E, use cycloneive. Cyclone V and Arria 10 GX devices are experimental, use it with a10gx argument. -top <module> use the specified module as top module (default='top') -vqm <file> write the design to the specified Verilog Quartus Mapping File. Writing of an output file is omitted if this parameter is not specified. -vpr <file> write BLIF files for VPR flow experiments. The synthesized BLIF output file is not compatible with the Quartus flow. Writing of an output file is omitted if this parameter is not specified. -run <from_label>:<to_label> only run the commands between the labels (see below). an empty from label is synonymous to 'begin', and empty to label is synonymous to the end of the command list. -noiopads do not use altsyncram cells in output netlist -nobram do not use altsyncram cells in output netlist -noflatten do not flatten design before synthesis -retime run 'abc' with -dff option The following commands are executed by this synthesis command: begin: family: read_verilog -sv -lib +/intel/max10/cells_sim.v read_verilog -sv -lib +/intel/common/m9k_bb.v read_verilog -sv -lib +/intel/common/altpll_bb.v hierarchy -check -top <top> flatten: (unless -noflatten) proc flatten tribuf -logic deminout coarse: synth -run coarse bram: (skip if -nobram) memory_bram -rules +/intel/common/brams.txt techmap -map +/intel/common/brams_map.v fine: opt -fast -mux_undef -undriven -fine -full memory_map opt -undriven -fine dffsr2dff dff2dffe -direct-match $_DFF_* opt -fine techmap -map +/techmap.v opt -full clean -purge setundef -undriven -zero abc -markgroups -dff (only if -retime) map_luts: abc -lut 4 clean map_cells: iopadmap -bits -outpad $__outpad I:O -inpad $__inpad O:I (unless -noiopads) techmap -map +/intel/max10/cells_map.v dffinit -highlow -ff dffeas q power_up clean -purge check: hierarchy -check stat check -noinit vqm: write_verilog -attr2comment -defparam -nohex -decimal -renameprefix syn_ <file-name> vpr: opt_clean -purge write_blif <file-name> \end{lstlisting} \section{synth\_xilinx -- synthesis for Xilinx FPGAs} \label{cmd:synth_xilinx} \begin{lstlisting}[numbers=left,frame=single] synth_xilinx [options] This command runs synthesis for Xilinx FPGAs. This command does not operate on partly selected designs. At the moment this command creates netlists that are compatible with 7-Series Xilinx devices. -top <module> use the specified module as top module -edif <file> write the design to the specified edif file. writing of an output file is omitted if this parameter is not specified. -blif <file> write the design to the specified BLIF file. writing of an output file is omitted if this parameter is not specified. -vpr generate an output netlist (and BLIF file) suitable for VPR (this feature is experimental and incomplete) -run <from_label>:<to_label> only run the commands between the labels (see below). an empty from label is synonymous to 'begin', and empty to label is synonymous to the end of the command list. -flatten flatten design before synthesis -retime run 'abc' with -dff option The following commands are executed by this synthesis command: begin: read_verilog -lib +/xilinx/cells_sim.v read_verilog -lib +/xilinx/cells_xtra.v read_verilog -lib +/xilinx/brams_bb.v hierarchy -check -top <top> flatten: (only if -flatten) proc flatten coarse: synth -run coarse bram: memory_bram -rules +/xilinx/brams.txt techmap -map +/xilinx/brams_map.v dram: memory_bram -rules +/xilinx/drams.txt techmap -map +/xilinx/drams_map.v fine: opt -fast -full memory_map dffsr2dff dff2dffe opt -full techmap -map +/techmap.v -map +/xilinx/arith_map.v opt -fast map_luts: abc -luts 2:2,3,6:5,10,20 [-dff] clean map_cells: techmap -map +/xilinx/cells_map.v (with -D NO_LUT in vpr mode) dffinit -ff FDRE Q INIT -ff FDCE Q INIT -ff FDPE Q INIT clean check: hierarchy -check stat check -noinit edif: (only if -edif) write_edif <file-name> blif: (only if -blif) write_blif <file-name> \end{lstlisting} \section{tcl -- execute a TCL script file} \label{cmd:tcl} \begin{lstlisting}[numbers=left,frame=single] tcl <filename> This command executes the tcl commands in the specified file. Use 'yosys cmd' to run the yosys command 'cmd' from tcl. The tcl command 'yosys -import' can be used to import all yosys commands directly as tcl commands to the tcl shell. Yosys commands 'proc' and 'rename' are wrapped to tcl commands 'procs' and 'renames' in order to avoid a name collision with the built in commands. \end{lstlisting} \section{techmap -- generic technology mapper} \label{cmd:techmap} \begin{lstlisting}[numbers=left,frame=single] techmap [-map filename] [selection] This pass implements a very simple technology mapper that replaces cells in the design with implementations given in form of a Verilog or ilang source file. -map filename the library of cell implementations to be used. without this parameter a builtin library is used that transforms the internal RTL cells to the internal gate library. -map %<design-name> like -map above, but with an in-memory design instead of a file. -extern load the cell implementations as separate modules into the design instead of inlining them. -max_iter <number> only run the specified number of iterations. -recursive instead of the iterative breadth-first algorithm use a recursive depth-first algorithm. both methods should yield equivalent results, but may differ in performance. -autoproc Automatically call "proc" on implementations that contain processes. -assert this option will cause techmap to exit with an error if it can't map a selected cell. only cell types that end on an underscore are accepted as final cell types by this mode. -D <define>, -I <incdir> this options are passed as-is to the Verilog frontend for loading the map file. Note that the Verilog frontend is also called with the '-nooverwrite' option set. When a module in the map file has the 'techmap_celltype' attribute set, it will match cells with a type that match the text value of this attribute. Otherwise the module name will be used to match the cell. When a module in the map file has the 'techmap_simplemap' attribute set, techmap will use 'simplemap' (see 'help simplemap') to map cells matching the module. When a module in the map file has the 'techmap_maccmap' attribute set, techmap will use 'maccmap' (see 'help maccmap') to map cells matching the module. When a module in the map file has the 'techmap_wrap' attribute set, techmap will create a wrapper for the cell and then run the command string that the attribute is set to on the wrapper module. All wires in the modules from the map file matching the pattern _TECHMAP_* or *._TECHMAP_* are special wires that are used to pass instructions from the mapping module to the techmap command. At the moment the following special wires are supported: _TECHMAP_FAIL_ When this wire is set to a non-zero constant value, techmap will not use this module and instead try the next module with a matching 'techmap_celltype' attribute. When such a wire exists but does not have a constant value after all _TECHMAP_DO_* commands have been executed, an error is generated. _TECHMAP_DO_* This wires are evaluated in alphabetical order. The constant text value of this wire is a yosys command (or sequence of commands) that is run by techmap on the module. A common use case is to run 'proc' on modules that are written using always-statements. When such a wire has a non-constant value at the time it is to be evaluated, an error is produced. That means it is possible for such a wire to start out as non-constant and evaluate to a constant value during processing of other _TECHMAP_DO_* commands. A _TECHMAP_DO_* command may start with the special token 'CONSTMAP; '. in this case techmap will create a copy for each distinct configuration of constant inputs and shorted inputs at this point and import the constant and connected bits into the map module. All further commands are executed in this copy. This is a very convenient way of creating optimized specializations of techmap modules without using the special parameters described below. A _TECHMAP_DO_* command may start with the special token 'RECURSION; '. then techmap will recursively replace the cells in the module with their implementation. This is not affected by the -max_iter option. It is possible to combine both prefixes to 'RECURSION; CONSTMAP; '. In addition to this special wires, techmap also supports special parameters in modules in the map file: _TECHMAP_CELLTYPE_ When a parameter with this name exists, it will be set to the type name of the cell that matches the module. _TECHMAP_CONSTMSK_<port-name>_ _TECHMAP_CONSTVAL_<port-name>_ When this pair of parameters is available in a module for a port, then former has a 1-bit for each constant input bit and the latter has the value for this bit. The unused bits of the latter are set to undef (x). _TECHMAP_BITS_CONNMAP_ _TECHMAP_CONNMAP_<port-name>_ For an N-bit port, the _TECHMAP_CONNMAP_<port-name>_ parameter, if it exists, will be set to an N*_TECHMAP_BITS_CONNMAP_ bit vector containing N words (of _TECHMAP_BITS_CONNMAP_ bits each) that assign each single bit driver a unique id. The values 0-3 are reserved for 0, 1, x, and z. This can be used to detect shorted inputs. When a module in the map file has a parameter where the according cell in the design has a port, the module from the map file is only used if the port in the design is connected to a constant value. The parameter is then set to the constant value. A cell with the name _TECHMAP_REPLACE_ in the map file will inherit the name and attributes of the cell that is being replaced. See 'help extract' for a pass that does the opposite thing. See 'help flatten' for a pass that does flatten the design (which is essentially techmap but using the design itself as map library). \end{lstlisting} \section{tee -- redirect command output to file} \label{cmd:tee} \begin{lstlisting}[numbers=left,frame=single] tee [-q] [-o logfile|-a logfile] cmd Execute the specified command, optionally writing the commands output to the specified logfile(s). -q Do not print output to the normal destination (console and/or log file) -o logfile Write output to this file, truncate if exists. -a logfile Write output to this file, append if exists. +INT, -INT Add/subract INT from the -v setting for this command. \end{lstlisting} \section{test\_abcloop -- automatically test handling of loops in abc command} \label{cmd:test_abcloop} \begin{lstlisting}[numbers=left,frame=single] test_abcloop [options] Test handling of logic loops in ABC. -n {integer} create this number of circuits and test them (default = 100). -s {positive_integer} use this value as rng seed value (default = unix time). \end{lstlisting} \section{test\_autotb -- generate simple test benches} \label{cmd:test_autotb} \begin{lstlisting}[numbers=left,frame=single] test_autotb [options] [filename] Automatically create primitive Verilog test benches for all modules in the design. The generated testbenches toggle the input pins of the module in a semi-random manner and dumps the resulting output signals. This can be used to check the synthesis results for simple circuits by comparing the testbench output for the input files and the synthesis results. The backend automatically detects clock signals. Additionally a signal can be forced to be interpreted as clock signal by setting the attribute 'gentb_clock' on the signal. The attribute 'gentb_constant' can be used to force a signal to a constant value after initialization. This can e.g. be used to force a reset signal low in order to explore more inner states in a state machine. -n <int> number of iterations the test bench should run (default = 1000) \end{lstlisting} \section{test\_cell -- automatically test the implementation of a cell type} \label{cmd:test_cell} \begin{lstlisting}[numbers=left,frame=single] test_cell [options] {cell-types} Tests the internal implementation of the given cell type (for example '$add') by comparing SAT solver, EVAL and TECHMAP implementations of the cell types.. Run with 'all' instead of a cell type to run the test on all supported cell types. Use for example 'all /$add' for all cell types except $add. -n {integer} create this number of cell instances and test them (default = 100). -s {positive_integer} use this value as rng seed value (default = unix time). -f {ilang_file} don't generate circuits. instead load the specified ilang file. -w {filename_prefix} don't test anything. just generate the circuits and write them to ilang files with the specified prefix -map {filename} pass this option to techmap. -simlib use "techmap -D SIMLIB_NOCHECKS -map +/simlib.v -max_iter 2 -autoproc" -aigmap instead of calling "techmap", call "aigmap" -muxdiv when creating test benches with dividers, create an additional mux to mask out the division-by-zero case -script {script_file} instead of calling "techmap", call "script {script_file}". -const set some input bits to random constant values -nosat do not check SAT model or run SAT equivalence checking -noeval do not check const-eval models -edges test cell edges db creator against sat-based implementation -v print additional debug information to the console -vlog {filename} create a Verilog test bench to test simlib and write_verilog \end{lstlisting} \section{torder -- print cells in topological order} \label{cmd:torder} \begin{lstlisting}[numbers=left,frame=single] torder [options] [selection] This command prints the selected cells in topological order. -stop <cell_type> <cell_port> do not use the specified cell port in topological sorting -noautostop by default Q outputs of internal FF cells and memory read port outputs are not used in topological sorting. this option deactivates that. \end{lstlisting} \section{trace -- redirect command output to file} \label{cmd:trace} \begin{lstlisting}[numbers=left,frame=single] trace cmd Execute the specified command, logging all changes the command performs on the design in real time. \end{lstlisting} \section{tribuf -- infer tri-state buffers} \label{cmd:tribuf} \begin{lstlisting}[numbers=left,frame=single] tribuf [options] [selection] This pass transforms $mux cells with 'z' inputs to tristate buffers. -merge merge multiple tri-state buffers driving the same net into a single buffer. -logic convert tri-state buffers that do not drive output ports to non-tristate logic. this option implies -merge. \end{lstlisting} \section{uniquify -- create unique copies of modules} \label{cmd:uniquify} \begin{lstlisting}[numbers=left,frame=single] uniquify [selection] By default, a module that is instantiated by several other modules is only kept once in the design. This preserves the original modularity of the design and reduces the overall size of the design in memory. But it prevents certain optimizations and other operations on the design. This pass creates unique modules for all selected cells. The created modules are marked with the 'unique' attribute. This commands only operates on modules that by themself have the 'unique' attribute set (the 'top' module is unique implicitly). \end{lstlisting} \section{verific -- load Verilog and VHDL designs using Verific} \label{cmd:verific} \begin{lstlisting}[numbers=left,frame=single] verific {-vlog95|-vlog2k|-sv2005|-sv2009|-sv2012|-sv} <verilog-file>.. Load the specified Verilog/SystemVerilog files into Verific. All files specified in one call to this command are one compilation unit. Files passed to different calls to this command are treated as belonging to different compilation units. Additional -D<macro>[=<value>] options may be added after the option indicating the language version (and before file names) to set additional verilog defines. The macros SYNTHESIS and VERIFIC are defined implicitly. verific -formal <verilog-file>.. Like -sv, but define FORMAL instead of SYNTHESIS. verific {-vhdl87|-vhdl93|-vhdl2k|-vhdl2008|-vhdl} <vhdl-file>.. Load the specified VHDL files into Verific. verific -work <libname> {-sv|-vhdl|...} <hdl-file> Load the specified Verilog/SystemVerilog/VHDL file into the specified library. (default library when -work is not present: "work") verific -vlog-incdir <directory>.. Add Verilog include directories. verific -vlog-libdir <directory>.. Add Verilog library directories. Verific will search in this directories to find undefined modules. verific -vlog-define <macro>[=<value>].. Add Verilog defines. verific -vlog-undef <macro>.. Remove Verilog defines previously set with -vlog-define. verific -set-error <msg_id>.. verific -set-warning <msg_id>.. verific -set-info <msg_id>.. verific -set-ignore <msg_id>.. Set message severity. <msg_id> is the string in square brackets when a message is printed, such as VERI-1209. verific -import [options] <top-module>.. Elaborate the design for the specified top modules, import to Yosys and reset the internal state of Verific. Import options: -all Elaborate all modules, not just the hierarchy below the given top modules. With this option the list of modules to import is optional. -gates Create a gate-level netlist. -flatten Flatten the design in Verific before importing. -extnets Resolve references to external nets by adding module ports as needed. -autocover Generate automatic cover statements for all asserts -v, -vv Verbose log messages. (-vv is even more verbose than -v.) The following additional import options are useful for debugging the Verific bindings (for Yosys and/or Verific developers): -k Keep going after an unsupported verific primitive is found. The unsupported primitive is added as blockbox module to the design. This will also add all SVA related cells to the design parallel to the checker logic inferred by it. -V Import Verific netlist as-is without translating to Yosys cell types. -nosva Ignore SVA properties, do not infer checker logic. -L <int> Maximum number of ctrl bits for SVA checker FSMs (default=16). -n Keep all Verific names on instances and nets. By default only user-declared names are preserved. -d <dump_file> Dump the Verific netlist as a verilog file. Visit http://verific.com/ for more information on Verific. \end{lstlisting} \section{verilog\_defaults -- set default options for read\_verilog} \label{cmd:verilog_defaults} \begin{lstlisting}[numbers=left,frame=single] verilog_defaults -add [options] Add the specified options to the list of default options to read_verilog. verilog_defaults -clear Clear the list of Verilog default options. verilog_defaults -push verilog_defaults -pop Push or pop the list of default options to a stack. Note that -push does not imply -clear. \end{lstlisting} \section{verilog\_defines -- define and undefine verilog defines} \label{cmd:verilog_defines} \begin{lstlisting}[numbers=left,frame=single] verilog_defines [options] Define and undefine verilog preprocessor macros. -Dname[=definition] define the preprocessor symbol 'name' and set its optional value 'definition' -Uname[=definition] undefine the preprocessor symbol 'name' \end{lstlisting} \section{wreduce -- reduce the word size of operations if possible} \label{cmd:wreduce} \begin{lstlisting}[numbers=left,frame=single] wreduce [options] [selection] This command reduces the word size of operations. For example it will replace the 32 bit adders in the following code with adders of more appropriate widths: module test(input [3:0] a, b, c, output [7:0] y); assign y = a + b + c + 1; endmodule Options: -memx Do not change the width of memory address ports. Use this options in flows that use the 'memory_memx' pass. \end{lstlisting} \section{write\_aiger -- write design to AIGER file} \label{cmd:write_aiger} \begin{lstlisting}[numbers=left,frame=single] write_aiger [options] [filename] Write the current design to an AIGER file. The design must be flattened and must not contain any cell types except $_AND_, $_NOT_, simple FF types, $assert and $assume cells, and $initstate cells. $assert and $assume cells are converted to AIGER bad state properties and invariant constraints. -ascii write ASCII version of AGIER format -zinit convert FFs to zero-initialized FFs, adding additional inputs for uninitialized FFs. -miter design outputs are AIGER bad state properties -symbols include a symbol table in the generated AIGER file -map <filename> write an extra file with port and latch symbols -vmap <filename> like -map, but more verbose \end{lstlisting} \section{write\_blif -- write design to BLIF file} \label{cmd:write_blif} \begin{lstlisting}[numbers=left,frame=single] write_blif [options] [filename] Write the current design to an BLIF file. -top top_module set the specified module as design top module -buf <cell-type> <in-port> <out-port> use cells of type <cell-type> with the specified port names for buffers -unbuf <cell-type> <in-port> <out-port> replace buffer cells with the specified name and port names with a .names statement that models a buffer -true <cell-type> <out-port> -false <cell-type> <out-port> -undef <cell-type> <out-port> use the specified cell types to drive nets that are constant 1, 0, or undefined. when '-' is used as <cell-type>, then <out-port> specifies the wire name to be used for the constant signal and no cell driving that wire is generated. when '+' is used as <cell-type>, then <out-port> specifies the wire name to be used for the constant signal and a .names statement is generated to drive the wire. -noalias if a net name is aliasing another net name, then by default a net without fanout is created that is driven by the other net. This option suppresses the generation of this nets without fanout. The following options can be useful when the generated file is not going to be read by a BLIF parser but a custom tool. It is recommended to not name the output file *.blif when any of this options is used. -icells do not translate Yosys's internal gates to generic BLIF logic functions. Instead create .subckt or .gate lines for all cells. -gates print .gate instead of .subckt lines for all cells that are not instantiations of other modules from this design. -conn do not generate buffers for connected wires. instead use the non-standard .conn statement. -attr use the non-standard .attr statement to write cell attributes -param use the non-standard .param statement to write cell parameters -cname use the non-standard .cname statement to write cell names -iname, -iattr enable -cname and -attr functionality for .names statements (the .cname and .attr statements will be included in the BLIF output after the truth table for the .names statement) -blackbox write blackbox cells with .blackbox statement. -impltf do not write definitions for the $true, $false and $undef wires. \end{lstlisting} \section{write\_btor -- write design to BTOR file} \label{cmd:write_btor} \begin{lstlisting}[numbers=left,frame=single] write_btor [options] [filename] Write a BTOR description of the current design. -v Add comments and indentation to BTOR output file -s Output only a single bad property for all asserts \end{lstlisting} \section{write\_edif -- write design to EDIF netlist file} \label{cmd:write_edif} \begin{lstlisting}[numbers=left,frame=single] write_edif [options] [filename] Write the current design to an EDIF netlist file. -top top_module set the specified module as design top module -nogndvcc do not create "GND" and "VCC" cells. (this will produce an error if the design contains constant nets. use "hilomap" to map to custom constant drivers first) -pvector {par|bra|ang} sets the delimiting character for module port rename clauses to parentheses, square brackets, or angle brackets. Unfortunately there are different "flavors" of the EDIF file format. This command generates EDIF files for the Xilinx place&route tools. It might be necessary to make small modifications to this command when a different tool is targeted. \end{lstlisting} \section{write\_file -- write a text to a file} \label{cmd:write_file} \begin{lstlisting}[numbers=left,frame=single] write_file [options] output_file [input_file] Write the text from the input file to the output file. -a Append to output file (instead of overwriting) Inside a script the input file can also can a here-document: write_file hello.txt <<EOT Hello World! EOT \end{lstlisting} \section{write\_firrtl -- write design to a FIRRTL file} \label{cmd:write_firrtl} \begin{lstlisting}[numbers=left,frame=single] write_firrtl [options] [filename] Write a FIRRTL netlist of the current design. \end{lstlisting} \section{write\_ilang -- write design to ilang file} \label{cmd:write_ilang} \begin{lstlisting}[numbers=left,frame=single] write_ilang [filename] Write the current design to an 'ilang' file. (ilang is a text representation of a design in yosys's internal format.) -selected only write selected parts of the design. \end{lstlisting} \section{write\_intersynth -- write design to InterSynth netlist file} \label{cmd:write_intersynth} \begin{lstlisting}[numbers=left,frame=single] write_intersynth [options] [filename] Write the current design to an 'intersynth' netlist file. InterSynth is a tool for Coarse-Grain Example-Driven Interconnect Synthesis. -notypes do not generate celltypes and conntypes commands. i.e. just output the netlists. this is used for postsilicon synthesis. -lib <verilog_or_ilang_file> Use the specified library file for determining whether cell ports are inputs or outputs. This option can be used multiple times to specify more than one library. -selected only write selected modules. modules must be selected entirely or not at all. http://www.clifford.at/intersynth/ \end{lstlisting} \section{write\_json -- write design to a JSON file} \label{cmd:write_json} \begin{lstlisting}[numbers=left,frame=single] write_json [options] [filename] Write a JSON netlist of the current design. -aig include AIG models for the different gate types The general syntax of the JSON output created by this command is as follows: { "modules": { <module_name>: { "ports": { <port_name>: <port_details>, ... }, "cells": { <cell_name>: <cell_details>, ... }, "netnames": { <net_name>: <net_details>, ... } } }, "models": { ... }, } Where <port_details> is: { "direction": <"input" | "output" | "inout">, "bits": <bit_vector> } And <cell_details> is: { "hide_name": <1 | 0>, "type": <cell_type>, "parameters": { <parameter_name>: <parameter_value>, ... }, "attributes": { <attribute_name>: <attribute_value>, ... }, "port_directions": { <port_name>: <"input" | "output" | "inout">, ... }, "connections": { <port_name>: <bit_vector>, ... }, } And <net_details> is: { "hide_name": <1 | 0>, "bits": <bit_vector> } The "hide_name" fields are set to 1 when the name of this cell or net is automatically created and is likely not of interest for a regular user. The "port_directions" section is only included for cells for which the interface is known. Module and cell ports and nets can be single bit wide or vectors of multiple bits. Each individual signal bit is assigned a unique integer. The <bit_vector> values referenced above are vectors of this integers. Signal bits that are connected to a constant driver are denoted as string "0" or "1" instead of a number. Numeric parameter and attribute values up to 32 bits are written as decimal values. Numbers larger than that are written as string holding the binary representation of the value. For example the following Verilog code: module test(input x, y); (* keep *) foo #(.P(42), .Q(1337)) foo_inst (.A({x, y}), .B({y, x}), .C({4'd10, {4{x}}})); endmodule Translates to the following JSON output: { "modules": { "test": { "ports": { "x": { "direction": "input", "bits": [ 2 ] }, "y": { "direction": "input", "bits": [ 3 ] } }, "cells": { "foo_inst": { "hide_name": 0, "type": "foo", "parameters": { "Q": 1337, "P": 42 }, "attributes": { "keep": 1, "src": "test.v:2" }, "connections": { "C": [ 2, 2, 2, 2, "0", "1", "0", "1" ], "B": [ 2, 3 ], "A": [ 3, 2 ] } } }, "netnames": { "y": { "hide_name": 0, "bits": [ 3 ], "attributes": { "src": "test.v:1" } }, "x": { "hide_name": 0, "bits": [ 2 ], "attributes": { "src": "test.v:1" } } } } } } The models are given as And-Inverter-Graphs (AIGs) in the following form: "models": { <model_name>: [ /* 0 */ [ <node-spec> ], /* 1 */ [ <node-spec> ], /* 2 */ [ <node-spec> ], ... ], ... }, The following node-types may be used: [ "port", <portname>, <bitindex>, <out-list> ] - the value of the specified input port bit [ "nport", <portname>, <bitindex>, <out-list> ] - the inverted value of the specified input port bit [ "and", <node-index>, <node-index>, <out-list> ] - the ANDed value of the specified nodes [ "nand", <node-index>, <node-index>, <out-list> ] - the inverted ANDed value of the specified nodes [ "true", <out-list> ] - the constant value 1 [ "false", <out-list> ] - the constant value 0 All nodes appear in topological order. I.e. only nodes with smaller indices are referenced by "and" and "nand" nodes. The optional <out-list> at the end of a node specification is a list of output portname and bitindex pairs, specifying the outputs driven by this node. For example, the following is the model for a 3-input 3-output $reduce_and cell inferred by the following code: module test(input [2:0] in, output [2:0] out); assign in = &out; endmodule "$reduce_and:3U:3": [ /* 0 */ [ "port", "A", 0 ], /* 1 */ [ "port", "A", 1 ], /* 2 */ [ "and", 0, 1 ], /* 3 */ [ "port", "A", 2 ], /* 4 */ [ "and", 2, 3, "Y", 0 ], /* 5 */ [ "false", "Y", 1, "Y", 2 ] ] Future version of Yosys might add support for additional fields in the JSON format. A program processing this format must ignore all unknown fields. \end{lstlisting} \section{write\_simplec -- convert design to simple C code} \label{cmd:write_simplec} \begin{lstlisting}[numbers=left,frame=single] write_simplec [options] [filename] Write simple C code for simulating the design. The C code writen can be used to simulate the design in a C environment, but the purpose of this command is to generate code that works well with C-based formal verification. -verbose this will print the recursive walk used to export the modules. -i8, -i16, -i32, -i64 set the maximum integer bit width to use in the generated code. THIS COMMAND IS UNDER CONSTRUCTION \end{lstlisting} \section{write\_smt2 -- write design to SMT-LIBv2 file} \label{cmd:write_smt2} \begin{lstlisting}[numbers=left,frame=single] write_smt2 [options] [filename] Write a SMT-LIBv2 [1] description of the current design. For a module with name '<mod>' this will declare the sort '<mod>_s' (state of the module) and will define and declare functions operating on that state. The following SMT2 functions are generated for a module with name '<mod>'. Some declarations/definitions are printed with a special comment. A prover using the SMT2 files can use those comments to collect all relevant metadata about the design. ; yosys-smt2-module <mod> (declare-sort |<mod>_s| 0) The sort representing a state of module <mod>. (define-fun |<mod>_h| ((state |<mod>_s|)) Bool (...)) This function must be asserted for each state to establish the design hierarchy. ; yosys-smt2-input <wirename> <width> ; yosys-smt2-output <wirename> <width> ; yosys-smt2-register <wirename> <width> ; yosys-smt2-wire <wirename> <width> (define-fun |<mod>_n <wirename>| (|<mod>_s|) (_ BitVec <width>)) (define-fun |<mod>_n <wirename>| (|<mod>_s|) Bool) For each port, register, and wire with the 'keep' attribute set an accessor function is generated. Single-bit wires are returned as Bool, multi-bit wires as BitVec. ; yosys-smt2-cell <submod> <instancename> (declare-fun |<mod>_h <instancename>| (|<mod>_s|) |<submod>_s|) There is a function like that for each hierarchical instance. It returns the sort that represents the state of the sub-module that implements the instance. (declare-fun |<mod>_is| (|<mod>_s|) Bool) This function must be asserted 'true' for initial states, and 'false' otherwise. (define-fun |<mod>_i| ((state |<mod>_s|)) Bool (...)) This function must be asserted 'true' for initial states. For non-initial states it must be left unconstrained. (define-fun |<mod>_t| ((state |<mod>_s|) (next_state |<mod>_s|)) Bool (...)) This function evaluates to 'true' if the states 'state' and 'next_state' form a valid state transition. (define-fun |<mod>_a| ((state |<mod>_s|)) Bool (...)) This function evaluates to 'true' if all assertions hold in the state. (define-fun |<mod>_u| ((state |<mod>_s|)) Bool (...)) This function evaluates to 'true' if all assumptions hold in the state. ; yosys-smt2-assert <id> <filename:linenum> (define-fun |<mod>_a <id>| ((state |<mod>_s|)) Bool (...)) Each $assert cell is converted into one of this functions. The function evaluates to 'true' if the assert statement holds in the state. ; yosys-smt2-assume <id> <filename:linenum> (define-fun |<mod>_u <id>| ((state |<mod>_s|)) Bool (...)) Each $assume cell is converted into one of this functions. The function evaluates to 'true' if the assume statement holds in the state. ; yosys-smt2-cover <id> <filename:linenum> (define-fun |<mod>_c <id>| ((state |<mod>_s|)) Bool (...)) Each $cover cell is converted into one of this functions. The function evaluates to 'true' if the cover statement is activated in the state. Options: -verbose this will print the recursive walk used to export the modules. -stbv Use a BitVec sort to represent a state instead of an uninterpreted sort. As a side-effect this will prevent use of arrays to model memories. -stdt Use SMT-LIB 2.6 style datatypes to represent a state instead of an uninterpreted sort. -nobv disable support for BitVec (FixedSizeBitVectors theory). without this option multi-bit wires are represented using the BitVec sort and support for coarse grain cells (incl. arithmetic) is enabled. -nomem disable support for memories (via ArraysEx theory). this option is implied by -nobv. only $mem cells without merged registers in read ports are supported. call "memory" with -nordff to make sure that no registers are merged into $mem read ports. '<mod>_m' functions will be generated for accessing the arrays that are used to represent memories. -wires create '<mod>_n' functions for all public wires. by default only ports, registers, and wires with the 'keep' attribute are exported. -tpl <template_file> use the given template file. the line containing only the token '%%' is replaced with the regular output of this command. [1] For more information on SMT-LIBv2 visit http://smt-lib.org/ or read David R. Cok's tutorial: http://www.grammatech.com/resources/smt/SMTLIBTutorial.pdf --------------------------------------------------------------------------- Example: Consider the following module (test.v). We want to prove that the output can never transition from a non-zero value to a zero value. module test(input clk, output reg [3:0] y); always @(posedge clk) y <= (y << 1) | ^y; endmodule For this proof we create the following template (test.tpl). ; we need QF_UFBV for this poof (set-logic QF_UFBV) ; insert the auto-generated code here %% ; declare two state variables s1 and s2 (declare-fun s1 () test_s) (declare-fun s2 () test_s) ; state s2 is the successor of state s1 (assert (test_t s1 s2)) ; we are looking for a model with y non-zero in s1 (assert (distinct (|test_n y| s1) #b0000)) ; we are looking for a model with y zero in s2 (assert (= (|test_n y| s2) #b0000)) ; is there such a model? (check-sat) The following yosys script will create a 'test.smt2' file for our proof: read_verilog test.v hierarchy -check; proc; opt; check -assert write_smt2 -bv -tpl test.tpl test.smt2 Running 'cvc4 test.smt2' will print 'unsat' because y can never transition from non-zero to zero in the test design. \end{lstlisting} \section{write\_smv -- write design to SMV file} \label{cmd:write_smv} \begin{lstlisting}[numbers=left,frame=single] write_smv [options] [filename] Write an SMV description of the current design. -verbose this will print the recursive walk used to export the modules. -tpl <template_file> use the given template file. the line containing only the token '%%' is replaced with the regular output of this command. THIS COMMAND IS UNDER CONSTRUCTION \end{lstlisting} \section{write\_spice -- write design to SPICE netlist file} \label{cmd:write_spice} \begin{lstlisting}[numbers=left,frame=single] write_spice [options] [filename] Write the current design to an SPICE netlist file. -big_endian generate multi-bit ports in MSB first order (default is LSB first) -neg net_name set the net name for constant 0 (default: Vss) -pos net_name set the net name for constant 1 (default: Vdd) -nc_prefix prefix for not-connected nets (default: _NC) -inames include names of internal ($-prefixed) nets in outputs (default is to use net numbers instead) -top top_module set the specified module as design top module \end{lstlisting} \section{write\_table -- write design as connectivity table} \label{cmd:write_table} \begin{lstlisting}[numbers=left,frame=single] write_table [options] [filename] Write the current design as connectivity table. The output is a tab-separated ASCII table with the following columns: module name cell name cell type cell port direction signal module inputs and outputs are output using cell type and port '-' and with 'pi' (primary input) or 'po' (primary output) or 'pio' as direction. \end{lstlisting} \section{write\_verilog -- write design to Verilog file} \label{cmd:write_verilog} \begin{lstlisting}[numbers=left,frame=single] write_verilog [options] [filename] Write the current design to a Verilog file. -norename without this option all internal object names (the ones with a dollar instead of a backslash prefix) are changed to short names in the format '_<number>_'. -renameprefix <prefix> insert this prefix in front of auto-generated instance names -noattr with this option no attributes are included in the output -attr2comment with this option attributes are included as comments in the output -noexpr without this option all internal cells are converted to Verilog expressions. -nodec 32-bit constant values are by default dumped as decimal numbers, not bit pattern. This option deactivates this feature and instead will write out all constants in binary. -decimal dump 32-bit constants in decimal and without size and radix -nohex constant values that are compatible with hex output are usually dumped as hex values. This option deactivates this feature and instead will write out all constants in binary. -nostr Parameters and attributes that are specified as strings in the original input will be output as strings by this back-end. This deactivates this feature and instead will write string constants as binary numbers. -defparam Use 'defparam' statements instead of the Verilog-2001 syntax for cell parameters. -blackboxes usually modules with the 'blackbox' attribute are ignored. with this option set only the modules with the 'blackbox' attribute are written to the output file. -selected only write selected modules. modules must be selected entirely or not at all. -v verbose output (print new names of all renamed wires and cells) Note that RTLIL processes can't always be mapped directly to Verilog always blocks. This frontend should only be used to export an RTLIL netlist, i.e. after the "proc" pass has been used to convert all processes to logic networks and registers. A warning is generated when this command is called on a design with RTLIL processes. \end{lstlisting} \section{zinit -- add inverters so all FF are zero-initialized} \label{cmd:zinit} \begin{lstlisting}[numbers=left,frame=single] zinit [options] [selection] Add inverters as needed to make all FFs zero-initialized. -all also add zero initialization to uninitialized FFs \end{lstlisting}