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| author | Jannis Harder <me@jix.one> | 2022-06-29 17:53:58 +0200 |
|---|---|---|
| committer | Jannis Harder <me@jix.one> | 2022-06-30 12:09:04 +0200 |
| commit | 5db542742b8f69405417e5a715b4b72ce4c78534 (patch) | |
| tree | 00ad832cc6a32751142e1648bcb713b00656a7c2 | |
| parent | b80976b543fc9f19d8ac5e574b904f1f8c67cd49 (diff) | |
| download | yosys-5db542742b8f69405417e5a715b4b72ce4c78534.tar.gz yosys-5db542742b8f69405417e5a715b4b72ce4c78534.tar.bz2 yosys-5db542742b8f69405417e5a715b4b72ce4c78534.zip | |
async2sync: turn FFs with const clks into gclk FFs with feedback
The formal backends do not support multiple clocks. This includes
constant clocks. Constant clocks do appear in what isn't a proper
multiclock design, for example when mapping not fully initialized ROMs.
As converting FFs with constant clocks to FFs using the global is doable
even in a single clock flow, make async2sync do this.
| -rw-r--r-- | passes/sat/async2sync.cc | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/passes/sat/async2sync.cc b/passes/sat/async2sync.cc index 46c76eba9..6fdf470b1 100644 --- a/passes/sat/async2sync.cc +++ b/passes/sat/async2sync.cc @@ -75,6 +75,9 @@ struct Async2syncPass : public Pass { if (ff.has_gclk) continue; + if (ff.has_clk && ff.sig_clk.is_fully_const()) + ff.has_ce = ff.has_clk = ff.has_srst = false; + if (ff.has_clk) { if (ff.has_sr) { |