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Gowin. Reduce the range of flip-flop types.

Browse source 
UG303-1.0E_Arora Ⅴ Configurable Function Unit (CFU) User Guide.pdf
specifies that the only flip-flop types supported in GW5 are DFFSE,
DFFRE, DFFPE, and DFFCE.

However, the bit streams generated by the vendor IDE also contain DFF
flip-flops, which are probably the result of optimisation, so we leave
them in the list of permitted items, but add a flag that will allow the
generation of completely correct output files, acceptable for further P&
R using vendor tools (they will not allow the use of flip-flops other
than the four specified in the netlist).

In the GW5 SemiDual Port BSRAM series, the primitive does not have
RESETA and RESETB ports—they are replaced by the RESET port, so we
separate the files for BSRAM generation, especially since in the future
we may have to take into account other, as yet unexplored, differences
in BSRAM.

Signed-off-by: YRabbit <rabbit@yrabbit.cyou>
This commit is contained in:
YRabbit 2025-10-11 21:12:35 +10:00
parent 9a12d92551
commit 02e40e8118
3 changed files with 422 additions and 6 deletions
Download patch file Download diff file Expand all files Collapse all files

28
techlibs/gowin/synth_gowin.cc
View file

@ -57,6 +57,9 @@ struct SynthGowinPass : public ScriptPass
log(" -nodffe\n");
log(" do not use flipflops with CE in output netlist\n");
log("\n");
log(" -strict-gw5a-dffs\n");
log(" use only DFFSE/DFFRE/DFFPE/DFFCE flipflops for the GW5A family\n");
log("\n");
log(" -nobram\n");
log(" do not use BRAM cells in output netlist\n");
log("\n");
@ -97,7 +100,7 @@ struct SynthGowinPass : public ScriptPass
}
string top_opt, vout_file, json_file, family;
bool retime, nobram, nolutram, flatten, nodffe, nowidelut, abc9, noiopads, noalu, no_rw_check;
bool retime, nobram, nolutram, flatten, nodffe, strict_gw5a_dffs, nowidelut, abc9, noiopads, noalu, no_rw_check;
void clear_flags() override
{
@ -109,6 +112,7 @@ struct SynthGowinPass : public ScriptPass
flatten = true;
nobram = false;
nodffe = false;
strict_gw5a_dffs = false;
nolutram = false;
nowidelut = false;
abc9 = true;
@ -165,6 +169,10 @@ struct SynthGowinPass : public ScriptPass
nodffe = true;
continue;
}
if (args[argidx] == "-strict-gw5a-dffs") {
strict_gw5a_dffs = true;
continue;
}
if (args[argidx] == "-noflatten") {
flatten = false;
continue;
@ -248,7 +256,7 @@ struct SynthGowinPass : public ScriptPass
args += " -no-auto-distributed";
}
run("memory_libmap -lib +/gowin/lutrams.txt -lib +/gowin/brams.txt" + args, "(-no-auto-block if -nobram, -no-auto-distributed if -nolutram)");
run("techmap -map +/gowin/lutrams_map.v -map +/gowin/brams_map.v");
run(stringf("techmap -map +/gowin/lutrams_map.v -map +/gowin/brams_map%s.v", family == "gw5a" ? "_gw5a" : ""));
}
if (check_label("map_ffram"))
@ -276,10 +284,18 @@ struct SynthGowinPass : public ScriptPass
if (check_label("map_ffs"))
{
run("opt_clean");
if (nodffe)
run("dfflegalize -cell $_DFF_?_ 0 -cell $_SDFF_?P?_ r -cell $_DFF_?P?_ r");
else
run("dfflegalize -cell $_DFF_?_ 0 -cell $_DFFE_?P_ 0 -cell $_SDFF_?P?_ r -cell $_SDFFE_?P?P_ r -cell $_DFF_?P?_ r -cell $_DFFE_?P?P_ r");
if (family == "gw5a") {
if (strict_gw5a_dffs) {
run("dfflegalize -cell $_SDFFE_PP?P_ r -cell $_DFFE_PP?P_ r");
} else {
run("dfflegalize -cell $_DFF_?_ 0 -cell $_SDFFE_PP?P_ r -cell $_DFFE_PP?P_ r");
}
} else {
if (nodffe)
run("dfflegalize -cell $_DFF_?_ 0 -cell $_SDFF_?P?_ r -cell $_DFF_?P?_ r");
else
run("dfflegalize -cell $_DFF_?_ 0 -cell $_DFFE_?P_ 0 -cell $_SDFF_?P?_ r -cell $_SDFFE_?P?P_ r -cell $_DFF_?P?_ r -cell $_DFFE_?P?P_ r");
}
run("techmap -map +/gowin/cells_map.v");
run("opt_expr -mux_undef");
run("simplemap");