The new bitwise case equality (`$bweqx`) and bitwise mux (`$bwmux`)
cells enable compact encoding and decoding of 3-valued logic signals
using multiple 2-valued signals.
iverilog complains about implicitly truncating LUT when connecting it to
the `$bmux` A input. This explicitly truncates it to avoid that warning
without changing the behaviour otherwise.
* Change simlib's $mux cell to use the ternary operator as $_MUX_
already does
* Stop opt_expr -keepdc from changing S=x to S=0
* Change const eval of $mux and $pmux to match the updated simlib
(fixes sim)
* The sat behavior of $mux already matches the updated simlib
The verilog frontend uses $mux for the ternary operators and this
changes all interpreations of the $mux cell (that I found) to match the
verilog simulation behavior for the ternary operator. For 'if' and
'case' expressions the frontend may also use $mux but uses $eqx if the
verilog simulation behavior is requested with the '-ifx' option.
For $pmux there is a remaining mismatch between the sat behavior and the
simlib behavior. Resolving this requires more discussion, as the $pmux
cell does not directly correspond to a specific verilog construct.
Some builtin cells have an undefined (x) output even when all inputs are
defined. This is not natively supported by the formal backends which
will produce a fully defined value instead. This can lead to issues when
combining different backends in a formal flow. To work around these,
this adds a file containing verilog implementation of cells matching the
fully defined behavior implemented by the smt2 backend.
sf2 ff have no initial values, but some IP cores use initial values.
In order to use those cores on sf2, it is required to discard the
initial value (to be carefully used).
Uses the regex below to search (using vscode):
^\t\tlog\("(.{10,}(?<!\\n)|.{81,}\\n)"\);
Finds any log messages double indented (which help messages are)
and checks if *either* there are is no newline character at the end,
*or* the number of characters before the newline is more than 80.
These can be used to protect undefined flip-flop initialization values
from optimizations that are not sound for formal verification and can
help mapping all solver-provided values in witness traces for flows that
use different backends simultaneously.
Although the current style is allowed by the standard, Icarus verilog
doesn't parse default assignments using an implicit net type:
techlibs/ice40/cells_sim.v:305: syntax error
techlibs/ice40/cells_sim.v:1: Errors in port declarations.
Fix this by making sure that ports with default assignments first on
their line.
Fixes: 46d3f03d2 ("Add default assignments to other SB_* simulation models")
Signed-off-by: Sean Anderson <seanga2@gmail.com>
Anlogic FPGAs all have two kinds of BRAMs, one is 9bit*1K when being
true dual port (or 18bit*512 when simple dual port), the other is
16bit*2K.
Supports mapping of these two kinds of BRAMs. 9Kbit BRAM in SDP mode and
32Kbit BRAM with 8bit width are not support yet.
Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
* enable mixed read-width / write-width ports in SDP mode
* fix NO_CHANGE and WRITE_THROUGH behavior during read access
* remove redundant zero-initialization
* set A/B_WE bit during map (gatemate_bramopt pass could be removed later)
* differentiate "upper" and "lower" initialization for cascade mode
* remove unused techmap models in `map_regs.v`
* replace RAM initilization loops with 320-bit-writes
* add script to test targets in top-level Makefile
* remove `MAXWIDTH` parameter and treat both vector widths individually in `mult_map.v`
* iterate over all modules in `gatemate_bramopt` pass
* xilinx: add SCC test for DSP48E1
* xilinx: Gate DSP48E1 being a whitebox behind ALLOW_WHITEBOX_DSP48E1
Have a test that checks it works through ABC9 when enabled
* abc9 to break SCCs using $__ABC9_SCC_BREAKER module
* Add test
* abc9_ops: remove refs to (* abc9_keep *) on wires
* abc9_ops: do not bypass cells in an SCC
* Add myself to CODEOWNERS for abc9*
* Fix compile
* abc9_ops: run -prep_hier before scc
* Fix tests
* Remove bug reference pending fix
* abc9: fix for -prep_hier -dff
* xaiger: restore PI handling
* abc9_ops: -prep_xaiger sigmap
* abc9_ops: -mark_scc -> -break_scc
* abc9: eliminate hard-coded abc9.box from tests
Also tidy up
* Address review
This change set contains a number of bug fixes and improvements related to
scoping and resolution in generate and procedural blocks. While many of the
frontend changes are interdependent, it may be possible bring the techmap
changes in under a separate PR.
Declarations within unnamed generate blocks previously encountered issues
because the data declarations were left un-prefixed, breaking proper scoping.
The LRM outlines behavior for generating names for unnamed generate blocks. The
original goal was to add this implicit labelling, but doing so exposed a number
of issues downstream. Additional testing highlighted other closely related scope
resolution issues, which have been fixed. This change also adds support for
block item declarations within unnamed blocks in SystemVerilog mode.
1. Unlabled generate blocks are now implicitly named according to the LRM in
`label_genblks`, which is invoked at the beginning of module elaboration
2. The Verilog parser no longer wraps explicitly named generate blocks in a
synthetic unnamed generate block to avoid creating extra hierarchy levels
where they should not exist
3. The techmap phase now allows special control identifiers to be used outside
of the topmost scope, which is necessary because such wires and cells often
appear in unlabeled generate blocks, which now prefix the declarations within
4. Some techlibs required modifications because they relied on the previous
invalid scope resolution behavior
5. `expand_genblock` has been simplified, now only expanding the outermost
scope, completely deferring the inspection and elaboration of nested scopes;
names are now resolved by looking in the innermost scope and stepping outward
6. Loop variables now always become localparams during unrolling, allowing them
to be resolved and shadowed like any other identifier
7. Identifiers in synthetic function call scopes are now prefixed and resolved
in largely the same manner as other blocks
before: `$func$\func_01$tests/simple/scopes.blk.v:60$5$\blk\x`
after: `\func_01$func$tests/simple/scopes.v:60$5.blk.x`
8. Support identifiers referencing a local generate scope nested more
than 1 level deep, i.e. `B.C.x` while within generate scope `A`, or using a
prefix of a current or parent scope, i.e. `B.C.D.x` while in `A.B`, `A.B.C`,
or `A.B.C.D`
9. Variables can now be declared within unnamed blocks in SystemVerilog mode
Addresses the following issues: 656, 2423, 2493
martell
Miodrag Milanović
Jannis Harder
YRabbit
gatecat
TaoBi22
Tristan Gingold
KrystalDelusion
Sean Anderson
Marcelina Kościelnicka
Pepijn de Vos
Patrick Urban
Rick Luiken
Tim Pambor
Lofty
Xing GUO
Icenowy Zheng
Claire Xenia Wolf
Olivier Galibert
Eddie Hung
kittennbfive
ECP5-PCIe
Sylvain Munaut
Maciej Dudek
Adam Greig
Michael Christensen
Stefan Riesenberger
William D. Jones
Zachary Snow