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Improved dffsr2dff pass

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This commit is contained in:
Clifford Wolf 2016-02-02 19:42:49 +01:00
parent d69395ca08
commit 801c022457
1 changed files with 50 additions and 5 deletions
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55
passes/techmap/dffsr2dff.cc
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@ -23,7 +23,7 @@
USING_YOSYS_NAMESPACE
PRIVATE_NAMESPACE_BEGIN
void dffsr2dff_worker(SigMap &sigmap, Module *module, Cell *cell)
void dffsr_worker(SigMap &sigmap, Module *module, Cell *cell)
{
if (cell->type == "$dffsr")
{
@ -131,6 +131,49 @@ void dffsr2dff_worker(SigMap &sigmap, Module *module, Cell *cell)
}
}
void adff_worker(SigMap &sigmap, Module *module, Cell *cell)
{
if (cell->type == "$adff")
{
bool rstpol = cell->getParam("\\ARST_POLARITY").as_bool();
SigBit rstunused = rstpol ? State::S0 : State::S1;
SigSpec rstsig = sigmap(cell->getPort("\\ARST"));
if (rstsig != rstunused)
return;
log("Converting %s cell %s.%s to $dff.\n", log_id(cell->type), log_id(module), log_id(cell));
cell->type = "$dff";
cell->unsetPort("\\ARST");
cell->unsetParam("\\ARST_VALUE");
cell->unsetParam("\\ARST_POLARITY");
return;
}
if (cell->type.in("$_DFF_NN0_", "$_DFF_NN1_", "$_DFF_NP0_", "$_DFF_NP1_",
"$_DFF_PN0_", "$_DFF_PN1_", "$_DFF_PP0_", "$_DFF_PP1_"))
{
char clkpol = cell->type.c_str()[6];
char rstpol = cell->type.c_str()[7];
SigBit rstbit = sigmap(cell->getPort("\\R"));
SigBit rstunused = rstpol == 'P' ? State::S0 : State::S1;
if (rstbit != rstunused)
return;
IdString newtype = stringf("$_DFF_%c_", clkpol);
log("Converting %s cell %s.%s to %s.\n", log_id(cell->type), log_id(module), log_id(cell), log_id(newtype));
cell->type = newtype;
cell->unsetPort("\\R");
return;
}
}
struct Dffsr2dffPass : public Pass {
Dffsr2dffPass() : Pass("dffsr2dff", "convert DFFSR cells to simpler FF cell types") { }
virtual void help()
@ -139,8 +182,8 @@ struct Dffsr2dffPass : public Pass {
log("\n");
log(" dffsr2dff [options] [selection]\n");
log("\n");
log("This pass converts DFFSR cells ($dffsr, $_DFFSR_???_) to simpler FF cell types\n");
log("when one or both of the set/reset inputs is unused.\n");
log("This pass converts DFFSR cells ($dffsr, $_DFFSR_???_) and ADFF cells ($adff,\n");
log("$_DFF_???_) to simpler FF cell types when any of the set/reset inputs is unused.\n");
log("\n");
}
virtual void execute(std::vector<std::string> args, RTLIL::Design *design)
@ -159,8 +202,10 @@ struct Dffsr2dffPass : public Pass {
for (auto module : design->selected_modules()) {
SigMap sigmap(module);
for (auto cell : module->selected_cells())
dffsr2dff_worker(sigmap, module, cell);
for (auto cell : module->selected_cells()) {
dffsr_worker(sigmap, module, cell);
adff_worker(sigmap, module, cell);
}
}
}
} Dffsr2dffPass;