Docs: Formatting recent md -> rst converts

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Krystine Sherwin 2024-12-05 09:21:12 +13:00
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@ -9,19 +9,19 @@ Formatting of code
- Yosys code is using tabs for indentation. Tabs are 8 characters. - Yosys code is using tabs for indentation. Tabs are 8 characters.
- A continuation of a statement in the following line is indented by - A continuation of a statement in the following line is indented by two
two additional tabs. additional tabs.
- Lines are as long as you want them to be. A good rule of thumb is - Lines are as long as you want them to be. A good rule of thumb is to break
to break lines at about column 150. lines at about column 150.
- Opening braces can be put on the same or next line as the statement - Opening braces can be put on the same or next line as the statement opening
opening the block (if, switch, for, while, do). Put the opening brace the block (if, switch, for, while, do). Put the opening brace on its own line
on its own line for larger blocks, especially blocks that contains for larger blocks, especially blocks that contains blank lines.
blank lines.
- Otherwise stick to the Linux Kernel Coding Style: - Otherwise stick to the `Linux Kernel Coding Style`_.
https://www.kernel.org/doc/Documentation/process/coding-style.rst
.. _Linux Kernel Coding Style: https://www.kernel.org/doc/Documentation/process/coding-style.rst
C++ Language C++ Language
@ -29,8 +29,8 @@ C++ Language
Yosys is written in C++17. Yosys is written in C++17.
In general Yosys uses "int" instead of "size_t". To avoid compiler In general Yosys uses ``int`` instead of ``size_t``. To avoid compiler warnings
warnings for implicit type casts, always use "GetSize(foobar)" instead for implicit type casts, always use ``GetSize(foobar)`` instead of
of "foobar.size()". (GetSize() is defined in kernel/yosys.h) ``foobar.size()``. (``GetSize()`` is defined in :file:`kernel/yosys.h`)
Use range-based for loops whenever applicable. Use range-based for loops whenever applicable.

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@ -40,30 +40,31 @@ page`_.
* Tests allow refactoring; * Tests allow refactoring;
With those advantages in mind, it was required to choose a framework which fits With those advantages in mind, it was required to choose a framework which fits
well with C/C++ code. Hence, it was chosen (google test) well with C/C++ code. Hence, `google test`_ was chosen, because it is widely
[https://github.com/google/googletest], because it is largely used and it is used and it is relatively easy learn.
relatively easy learn.
.. _google test: https://github.com/google/googletest
Install and configure google test (manually) Install and configure google test (manually)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In this section, you will see a brief description of how to install google In this section, you will see a brief description of how to install google test.
test. However, it is strongly recommended that you take a look to the official However, it is strongly recommended that you take a look to the official
repository (https://github.com/google/googletest) and refers to that if you repository (https://github.com/google/googletest) and refers to that if you have
have any problem to install it. Follow the steps below: any problem to install it. Follow the steps below:
* Install: cmake and pthread * Install: cmake and pthread
* Clone google test project from: https://github.com/google/googletest and * Clone google test project from: https://github.com/google/googletest and enter
enter in the project directory in the project directory
* Inside project directory, type: * Inside project directory, type:
``` .. code-block:: console
cmake -DBUILD_SHARED_LIBS=ON .
make
```
* After compilation, copy all "*.so" inside directory "googlemock" and cmake -DBUILD_SHARED_LIBS=ON .
"googlemock/gtest" to "/usr/lib/" make
* After compilation, copy all ``*.so`` inside directory ``googlemock`` and
``googlemock/gtest`` to ``/usr/lib/``
* Done! Now you can compile your tests. * Done! Now you can compile your tests.
If you have any problem, go to the official repository to find help. If you have any problem, go to the official repository to find help.
@ -76,23 +77,25 @@ page`_.
If you want to add new unit tests for Yosys, just follow the steps below: If you want to add new unit tests for Yosys, just follow the steps below:
* Go to directory "yosys/test/unit/" * Go to directory :file:`test/unit/`
* In this directory you can find something similar Yosys's directory structure. * In this directory you can find something similar Yosys's directory structure.
To create your unit test file you have to follow this pattern: To create your unit test file you have to follow this pattern:
fileNameToImplementUnitTest + Test.cc. E.g.: if you want to implement the fileNameToImplementUnitTest + Test.cc. E.g.: if you want to implement the unit
unit test for kernel/celledges.cc, you will need to create a file like this: test for ``kernel/celledges.cc``, you will need to create a file like this:
tests/unit/kernel/celledgesTest.cc; ``tests/unit/kernel/celledgesTest.cc``;
* Implement your unit test * Implement your unit test
Run unit tests Run unit tests
~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~
To compile and run all unit tests, just go to yosys root directory and type: To compile and run all unit tests, just go to yosys root directory and type:
```
make unit-test .. code-block:: console
```
make unit-test
If you want to remove all unit test files, type: If you want to remove all unit test files, type:
```
make clean-unit-test .. code-block:: console
```
make clean-unit-test

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@ -21,64 +21,63 @@ for them:
Verilog Attributes and non-standard features Verilog Attributes and non-standard features
-------------------------------------------- --------------------------------------------
- The ``full_case`` attribute on case statements is supported - The ``full_case`` attribute on case statements is supported (also the
(also the non-standard ``// synopsys full_case`` directive) non-standard ``// synopsys full_case`` directive)
- The ``parallel_case`` attribute on case statements is supported - The ``parallel_case`` attribute on case statements is supported (also the
(also the non-standard ``// synopsys parallel_case`` directive) non-standard ``// synopsys parallel_case`` directive)
- The ``// synopsys translate_off`` and ``// synopsys translate_on`` - The ``// synopsys translate_off`` and ``// synopsys translate_on`` directives
directives are also supported (but the use of ``` `ifdef .. `endif ``` are also supported (but the use of ``` `ifdef .. `endif ``` is strongly
is strongly recommended instead). recommended instead).
- The ``nomem2reg`` attribute on modules or arrays prohibits the - The ``nomem2reg`` attribute on modules or arrays prohibits the automatic early
automatic early conversion of arrays to separate registers. This conversion of arrays to separate registers. This is potentially dangerous.
is potentially dangerous. Usually the front-end has good reasons Usually the front-end has good reasons for converting an array to a list of
for converting an array to a list of registers. Prohibiting this registers. Prohibiting this step will likely result in incorrect synthesis
step will likely result in incorrect synthesis results. results.
- The ``mem2reg`` attribute on modules or arrays forces the early - The ``mem2reg`` attribute on modules or arrays forces the early conversion of
conversion of arrays to separate registers. arrays to separate registers.
- The ``nomeminit`` attribute on modules or arrays prohibits the - The ``nomeminit`` attribute on modules or arrays prohibits the creation of
creation of initialized memories. This effectively puts ``mem2reg`` initialized memories. This effectively puts ``mem2reg`` on all memories that
on all memories that are written to in an ``initial`` block and are written to in an ``initial`` block and are not ROMs.
are not ROMs.
- The ``nolatches`` attribute on modules or always-blocks - The ``nolatches`` attribute on modules or always-blocks prohibits the
prohibits the generation of logic-loops for latches. Instead generation of logic-loops for latches. Instead all not explicitly assigned
all not explicitly assigned values default to x-bits. This does values default to x-bits. This does not affect clocked storage elements such
not affect clocked storage elements such as flip-flops. as flip-flops.
- The ``nosync`` attribute on registers prohibits the generation of a - The ``nosync`` attribute on registers prohibits the generation of a storage
storage element. The register itself will always have all bits set element. The register itself will always have all bits set to 'x' (undefined).
to 'x' (undefined). The variable may only be used as blocking assigned The variable may only be used as blocking assigned temporary variable within
temporary variable within an always block. This is mostly used internally an always block. This is mostly used internally by Yosys to synthesize Verilog
by Yosys to synthesize Verilog functions and access arrays. functions and access arrays.
- The ``nowrshmsk`` attribute on a register prohibits the generation of - The ``nowrshmsk`` attribute on a register prohibits the generation of
shift-and-mask type circuits for writing to bit slices of that register. shift-and-mask type circuits for writing to bit slices of that register.
- The ``onehot`` attribute on wires mark them as one-hot state register. This - The ``onehot`` attribute on wires mark them as one-hot state register. This is
is used for example for memory port sharing and set by the fsm_map pass. used for example for memory port sharing and set by the fsm_map pass.
- The ``blackbox`` attribute on modules is used to mark empty stub modules - The ``blackbox`` attribute on modules is used to mark empty stub modules that
that have the same ports as the real thing but do not contain information have the same ports as the real thing but do not contain information on the
on the internal configuration. This modules are only used by the synthesis internal configuration. This modules are only used by the synthesis passes to
passes to identify input and output ports of cells. The Verilog backend identify input and output ports of cells. The Verilog backend also does not
also does not output blackbox modules on default. ``read_verilog``, unless output blackbox modules on default. `read_verilog`, unless called with
called with ``-noblackbox`` will automatically set the blackbox attribute ``-noblackbox`` will automatically set the blackbox attribute on any empty
on any empty module it reads. module it reads.
- The ``noblackbox`` attribute set on an empty module prevents ``read_verilog`` - The ``noblackbox`` attribute set on an empty module prevents `read_verilog`
from automatically setting the blackbox attribute on the module. from automatically setting the blackbox attribute on the module.
- The ``whitebox`` attribute on modules triggers the same behavior as - The ``whitebox`` attribute on modules triggers the same behavior as
``blackbox``, but is for whitebox modules, i.e. library modules that ``blackbox``, but is for whitebox modules, i.e. library modules that contain a
contain a behavioral model of the cell type. behavioral model of the cell type.
- The ``lib_whitebox`` attribute overwrites ``whitebox`` when ``read_verilog`` - The ``lib_whitebox`` attribute overwrites ``whitebox`` when `read_verilog` is
is run in `-lib` mode. Otherwise it's automatically removed. run in ``-lib`` mode. Otherwise it's automatically removed.
- The ``dynports`` attribute is used by the Verilog front-end to mark modules - The ``dynports`` attribute is used by the Verilog front-end to mark modules
that have ports with a width that depends on a parameter. that have ports with a width that depends on a parameter.
@ -94,7 +93,7 @@ Verilog Attributes and non-standard features
Setting the ``keep`` attribute on a module has the same effect as setting it Setting the ``keep`` attribute on a module has the same effect as setting it
on all instances of the module. on all instances of the module.
- The ``keep_hierarchy`` attribute on cells and modules keeps the ``flatten`` - The ``keep_hierarchy`` attribute on cells and modules keeps the `flatten`
command from flattening the indicated cells and modules. command from flattening the indicated cells and modules.
- The `gate_cost_equivalent` attribute on a module can be used to specify - The `gate_cost_equivalent` attribute on a module can be used to specify
@ -106,63 +105,62 @@ Verilog Attributes and non-standard features
initialized "FPGA-style" with ``reg foo = val``. It can be used during initialized "FPGA-style" with ``reg foo = val``. It can be used during
synthesis to add the necessary reset logic. synthesis to add the necessary reset logic.
- The ``top`` attribute on a module marks this module as the top of the - The ``top`` attribute on a module marks this module as the top of the design
design hierarchy. The ``hierarchy`` command sets this attribute when called hierarchy. The `hierarchy` command sets this attribute when called with
with ``-top``. Other commands, such as ``flatten`` and various backends ``-top``. Other commands, such as `flatten` and various backends use this
use this attribute to determine the top module. attribute to determine the top module.
- The ``src`` attribute is set on cells and wires created by to the string - The ``src`` attribute is set on cells and wires created by to the string
``<hdl-file-name>:<line-number>`` by the HDL front-end and is then carried ``<hdl-file-name>:<line-number>`` by the HDL front-end and is then carried
through the synthesis. When entities are combined, a new |-separated through the synthesis. When entities are combined, a new \|-separated string
string is created that contains all the string from the original entities. is created that contains all the strings from the original entities.
- The ``defaultvalue`` attribute is used to store default values for - The ``defaultvalue`` attribute is used to store default values for module
module inputs. The attribute is attached to the input wire by the HDL inputs. The attribute is attached to the input wire by the HDL front-end when
front-end when the input is declared with a default value. the input is declared with a default value.
- The ``parameter`` and ``localparam`` attributes are used to mark wires - The ``parameter`` and ``localparam`` attributes are used to mark wires that
that represent module parameters or localparams (when the HDL front-end represent module parameters or localparams (when the HDL front-end is run in
is run in ``-pwires`` mode). ``-pwires`` mode).
- Wires marked with the ``hierconn`` attribute are connected to wires with the - Wires marked with the ``hierconn`` attribute are connected to wires with the
same name (format ``cell_name.identifier``) when they are imported from same name (format ``cell_name.identifier``) when they are imported from
sub-modules by ``flatten``. sub-modules by `flatten`.
- The ``clkbuf_driver`` attribute can be set on an output port of a blackbox - The ``clkbuf_driver`` attribute can be set on an output port of a blackbox
module to mark it as a clock buffer output, and thus prevent ``clkbufmap`` module to mark it as a clock buffer output, and thus prevent `clkbufmap` from
from inserting another clock buffer on a net driven by such output. inserting another clock buffer on a net driven by such output.
- The ``clkbuf_sink`` attribute can be set on an input port of a module to - The ``clkbuf_sink`` attribute can be set on an input port of a module to
request clock buffer insertion by the ``clkbufmap`` pass. request clock buffer insertion by the `clkbufmap` pass.
- The ``clkbuf_inv`` attribute can be set on an output port of a module - The ``clkbuf_inv`` attribute can be set on an output port of a module with the
with the value set to the name of an input port of that module. When value set to the name of an input port of that module. When the `clkbufmap`
the ``clkbufmap`` would otherwise insert a clock buffer on this output, would otherwise insert a clock buffer on this output, it will instead try
it will instead try inserting the clock buffer on the input port (this inserting the clock buffer on the input port (this is used to implement clock
is used to implement clock inverter cells that clock buffer insertion inverter cells that clock buffer insertion will "see through").
will "see through").
- The ``clkbuf_inhibit`` is the default attribute to set on a wire to prevent - The ``clkbuf_inhibit`` is the default attribute to set on a wire to prevent
automatic clock buffer insertion by ``clkbufmap``. This behaviour can be automatic clock buffer insertion by `clkbufmap`. This behaviour can be
overridden by providing a custom selection to ``clkbufmap``. overridden by providing a custom selection to `clkbufmap`.
- The ``invertible_pin`` attribute can be set on a port to mark it as - The ``invertible_pin`` attribute can be set on a port to mark it as invertible
invertible via a cell parameter. The name of the inversion parameter via a cell parameter. The name of the inversion parameter is specified as the
is specified as the value of this attribute. The value of the inversion value of this attribute. The value of the inversion parameter must be of the
parameter must be of the same width as the port, with 1 indicating same width as the port, with 1 indicating an inverted bit and 0 indicating a
an inverted bit and 0 indicating a non-inverted bit. non-inverted bit.
- The ``iopad_external_pin`` attribute on a blackbox module's port marks - The ``iopad_external_pin`` attribute on a blackbox module's port marks it as
it as the external-facing pin of an I/O pad, and prevents ``iopadmap`` the external-facing pin of an I/O pad, and prevents `iopadmap` from inserting
from inserting another pad cell on it. another pad cell on it.
- The module attribute ``abc9_lut`` is an integer attribute indicating to - The module attribute ``abc9_lut`` is an integer attribute indicating to `abc9`
`abc9` that this module describes a LUT with an area cost of this value, and that this module describes a LUT with an area cost of this value, and
propagation delays described using `specify` statements. propagation delays described using ``specify`` statements.
- The module attribute ``abc9_box`` is a boolean specifying a black/white-box - The module attribute ``abc9_box`` is a boolean specifying a black/white-box
definition, with propagation delays described using `specify` statements, for definition, with propagation delays described using ``specify`` statements,
use by `abc9`. for use by `abc9`.
- The port attribute ``abc9_carry`` marks the carry-in (if an input port) and - The port attribute ``abc9_carry`` marks the carry-in (if an input port) and
carry-out (if output port) ports of a box. This information is necessary for carry-out (if output port) ports of a box. This information is necessary for
@ -179,38 +177,41 @@ Verilog Attributes and non-standard features
``proc_dlatch``. ``proc_dlatch``.
- The cell attribute ``wildcard_port_conns`` represents wildcard port - The cell attribute ``wildcard_port_conns`` represents wildcard port
connections (SystemVerilog ``.*``). These are resolved to concrete connections (SystemVerilog ``.*``). These are resolved to concrete connections
connections to matching wires in ``hierarchy``. to matching wires in `hierarchy`.
- In addition to the ``(* ... *)`` attribute syntax, Yosys supports - In addition to the ``(* ... *)`` attribute syntax, Yosys supports the
the non-standard ``{* ... *}`` attribute syntax to set default attributes non-standard ``{* ... *}`` attribute syntax to set default attributes for
for everything that comes after the ``{* ... *}`` statement. (Reset everything that comes after the ``{* ... *}`` statement. (Reset by adding an
by adding an empty ``{* *}`` statement.) empty ``{* *}`` statement.)
- In module parameter and port declarations, and cell port and parameter - In module parameter and port declarations, and cell port and parameter lists,
lists, a trailing comma is ignored. This simplifies writing Verilog code a trailing comma is ignored. This simplifies writing Verilog code generators a
generators a bit in some cases. bit in some cases.
- Modules can be declared with ``module mod_name(...);`` (with three dots - Modules can be declared with ``module mod_name(...);`` (with three dots
instead of a list of module ports). With this syntax it is sufficient instead of a list of module ports). With this syntax it is sufficient to
to simply declare a module port as 'input' or 'output' in the module simply declare a module port as 'input' or 'output' in the module body.
body.
- When defining a macro with `define, all text between triple double quotes - When defining a macro with ``\`define``, all text between triple double quotes
is interpreted as macro body, even if it contains unescaped newlines. The is interpreted as macro body, even if it contains unescaped newlines. The
triple double quotes are removed from the macro body. For example: triple double quotes are removed from the macro body. For example:
.. code-block:: verilog
`define MY_MACRO(a, b) """ `define MY_MACRO(a, b) """
assign a = 23; assign a = 23;
assign b = 42; assign b = 42;
""" """
- The attribute ``via_celltype`` can be used to implement a Verilog task or - The attribute ``via_celltype`` can be used to implement a Verilog task or
function by instantiating the specified cell type. The value is the name function by instantiating the specified cell type. The value is the name of
of the cell type to use. For functions the name of the output port can the cell type to use. For functions the name of the output port can be
be specified by appending it to the cell type separated by a whitespace. specified by appending it to the cell type separated by a whitespace. The body
The body of the task or function is unused in this case and can be used of the task or function is unused in this case and can be used to specify a
to specify a behavioral model of the cell type for simulation. For example: behavioral model of the cell type for simulation. For example:
.. code-block:: verilog
module my_add3(A, B, C, Y); module my_add3(A, B, C, Y);
parameter WIDTH = 8; parameter WIDTH = 8;
@ -235,24 +236,28 @@ Verilog Attributes and non-standard features
- The ``wiretype`` attribute is added by the verilog parser for wires of a - The ``wiretype`` attribute is added by the verilog parser for wires of a
typedef'd type to indicate the type identifier. typedef'd type to indicate the type identifier.
- Various ``enum_value_{value}`` attributes are added to wires of an enumerated type - Various ``enum_value_{value}`` attributes are added to wires of an enumerated
to give a map of possible enum items to their values. type to give a map of possible enum items to their values.
- The ``enum_base_type`` attribute is added to enum items to indicate which - The ``enum_base_type`` attribute is added to enum items to indicate which enum
enum they belong to (enums -- anonymous and otherwise -- are they belong to (enums -- anonymous and otherwise -- are automatically named
automatically named with an auto-incrementing counter). Note that enums with an auto-incrementing counter). Note that enums are currently not strongly
are currently not strongly typed. typed.
- A limited subset of DPI-C functions is supported. The plugin mechanism - A limited subset of DPI-C functions is supported. The plugin mechanism (see
(see ``help plugin``) can be used to load .so files with implementations ``help plugin``) can be used to load .so files with implementations of DPI-C
of DPI-C routines. As a non-standard extension it is possible to specify routines. As a non-standard extension it is possible to specify a plugin alias
a plugin alias using the ``<alias>:`` syntax. For example: using the ``<alias>:`` syntax. For example:
.. code-block:: verilog
module dpitest; module dpitest;
import "DPI-C" function foo:round = real my_round (real); import "DPI-C" function foo:round = real my_round (real);
parameter real r = my_round(12.345); parameter real r = my_round(12.345);
endmodule endmodule
.. code-block::
$ yosys -p 'plugin -a foo -i /lib/libm.so; read_verilog dpitest.v' $ yosys -p 'plugin -a foo -i /lib/libm.so; read_verilog dpitest.v'
- Sized constants (the syntax ``<size>'s?[bodh]<value>``) support constant - Sized constants (the syntax ``<size>'s?[bodh]<value>``) support constant
@ -261,17 +266,17 @@ Verilog Attributes and non-standard features
- The system tasks ``$finish``, ``$stop`` and ``$display`` are supported in - The system tasks ``$finish``, ``$stop`` and ``$display`` are supported in
initial blocks in an unconditional context (only if/case statements on initial blocks in an unconditional context (only if/case statements on
expressions over parameters and constant values are allowed). The intended expressions over parameters and constant values are allowed). The intended use
use for this is synthesis-time DRC. for this is synthesis-time DRC.
- There is limited support for converting ``specify`` .. ``endspecify`` - There is limited support for converting ``specify`` .. ``endspecify``
statements to special ``$specify2``, ``$specify3``, and ``$specrule`` cells, statements to special ``$specify2``, ``$specify3``, and ``$specrule`` cells,
for use in blackboxes and whiteboxes. Use ``read_verilog -specify`` to for use in blackboxes and whiteboxes. Use ``read_verilog -specify`` to enable
enable this functionality. (By default these blocks are ignored.) this functionality. (By default these blocks are ignored.)
- The ``reprocess_after`` internal attribute is used by the Verilog frontend to - The ``reprocess_after`` internal attribute is used by the Verilog frontend to
mark cells with bindings which might depend on the specified instantiated mark cells with bindings which might depend on the specified instantiated
module. Modules with such cells will be reprocessed during the ``hierarchy`` module. Modules with such cells will be reprocessed during the `hierarchy`
pass once the referenced module definition(s) become available. pass once the referenced module definition(s) become available.
- The ``smtlib2_module`` attribute can be set on a blackbox module to specify a - The ``smtlib2_module`` attribute can be set on a blackbox module to specify a
@ -279,6 +284,8 @@ Verilog Attributes and non-standard features
``smtlib2_comb_expr`` attribute can be used on output ports to define their ``smtlib2_comb_expr`` attribute can be used on output ports to define their
value using an SMT-LIB 2 expression. For example: value using an SMT-LIB 2 expression. For example:
.. code-block:: verilog
(* blackbox *) (* blackbox *)
(* smtlib2_module *) (* smtlib2_module *)
module submod(a, b); module submod(a, b);
@ -291,48 +298,49 @@ Non-standard or SystemVerilog features for formal verification
-------------------------------------------------------------- --------------------------------------------------------------
- Support for ``assert``, ``assume``, ``restrict``, and ``cover`` is enabled - Support for ``assert``, ``assume``, ``restrict``, and ``cover`` is enabled
when ``read_verilog`` is called with ``-formal``. when `read_verilog` is called with ``-formal``.
- The system task ``$initstate`` evaluates to 1 in the initial state and - The system task ``$initstate`` evaluates to 1 in the initial state and to 0
to 0 otherwise. otherwise.
- The system function ``$anyconst`` evaluates to any constant value. This is - The system function ``$anyconst`` evaluates to any constant value. This is
equivalent to declaring a reg as ``rand const``, but also works outside equivalent to declaring a reg as ``rand const``, but also works outside of
of checkers. (Yosys also supports ``rand const`` outside checkers.) checkers. (Yosys also supports ``rand const`` outside checkers.)
- The system function ``$anyseq`` evaluates to any value, possibly a different - The system function ``$anyseq`` evaluates to any value, possibly a different
value in each cycle. This is equivalent to declaring a reg as ``rand``, value in each cycle. This is equivalent to declaring a reg as ``rand``, but
but also works outside of checkers. (Yosys also supports ``rand`` also works outside of checkers. (Yosys also supports ``rand`` variables
variables outside checkers.) outside checkers.)
- The system functions ``$allconst`` and ``$allseq`` can be used to construct - The system functions ``$allconst`` and ``$allseq`` can be used to construct
formal exist-forall problems. Assumptions only hold if the trace satisfies formal exist-forall problems. Assumptions only hold if the trace satisfies the
the assumption for all ``$allconst/$allseq`` values. For assertions and cover assumption for all ``$allconst/$allseq`` values. For assertions and cover
statements it is sufficient if just one ``$allconst/$allseq`` value triggers statements it is sufficient if just one ``$allconst/$allseq`` value triggers
the property (similar to ``$anyconst/$anyseq``). the property (similar to ``$anyconst/$anyseq``).
- Wires/registers declared using the ``anyconst/anyseq/allconst/allseq`` attribute - Wires/registers declared using the ``anyconst/anyseq/allconst/allseq``
(for example ``(* anyconst *) reg [7:0] foobar;``) will behave as if driven attribute (for example ``(* anyconst *) reg [7:0] foobar;``) will behave as if
by a ``$anyconst/$anyseq/$allconst/$allseq`` function. driven by a ``$anyconst/$anyseq/$allconst/$allseq`` function.
- The SystemVerilog tasks ``$past``, ``$stable``, ``$rose`` and ``$fell`` are - The SystemVerilog tasks ``$past``, ``$stable``, ``$rose`` and ``$fell`` are
supported in any clocked block. supported in any clocked block.
- The syntax ``@($global_clock)`` can be used to create FFs that have no - The syntax ``@($global_clock)`` can be used to create FFs that have no
explicit clock input (``$ff`` cells). The same can be achieved by using explicit clock input (``$ff`` cells). The same can be achieved by using
``@(posedge <netname>)`` or ``@(negedge <netname>)`` when ``<netname>`` ``@(posedge <netname>)`` or ``@(negedge <netname>)`` when ``<netname>`` is
is marked with the ``(* gclk *)`` Verilog attribute. marked with the ``(* gclk *)`` Verilog attribute.
Supported features from SystemVerilog Supported features from SystemVerilog
------------------------------------- -------------------------------------
When ``read_verilog`` is called with ``-sv``, it accepts some language features When `read_verilog` is called with ``-sv``, it accepts some language features
from SystemVerilog: from SystemVerilog:
- The ``assert`` statement from SystemVerilog is supported in its most basic - The ``assert`` statement from SystemVerilog is supported in its most basic
form. In module context: ``assert property (<expression>);`` and within an form. In module context: ``assert property (<expression>);`` and within an
always block: ``assert(<expression>);``. It is transformed to an ``$assert`` cell. always block: ``assert(<expression>);``. It is transformed to an ``$assert``
cell.
- The ``assume``, ``restrict``, and ``cover`` statements from SystemVerilog are - The ``assume``, ``restrict``, and ``cover`` statements from SystemVerilog are
also supported. The same limitations as with the ``assert`` statement apply. also supported. The same limitations as with the ``assert`` statement apply.
@ -345,9 +353,9 @@ from SystemVerilog:
- Checkers without a port list that do not need to be instantiated (but instead - Checkers without a port list that do not need to be instantiated (but instead
behave like a named block) are supported. behave like a named block) are supported.
- SystemVerilog packages are supported. Once a SystemVerilog file is read - SystemVerilog packages are supported. Once a SystemVerilog file is read into a
into a design with ``read_verilog``, all its packages are available to design with `read_verilog`, all its packages are available to SystemVerilog
SystemVerilog files being read into the same design afterwards. files being read into the same design afterwards.
- typedefs are supported (including inside packages) - typedefs are supported (including inside packages)
- type casts are currently not supported - type casts are currently not supported