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| author | David Shah <dave@ds0.me> | 2019-12-07 12:14:34 +0000 |
|---|---|---|
| committer | David Shah <dave@ds0.me> | 2019-12-07 12:20:25 +0000 |
| commit | 349be76d2693f0c9527c6373d31fae7e711f9270 (patch) | |
| tree | 5f7ea45d2ba93c2cc1ebc57020a5ef36f4c14500 /ecp5/cells.cc | |
| parent | f0887427da28c4993b44e0e7f3e3ac39f29c16fd (diff) | |
| download | nextpnr-349be76d2693f0c9527c6373d31fae7e711f9270.tar.gz nextpnr-349be76d2693f0c9527c6373d31fae7e711f9270.tar.bz2 nextpnr-349be76d2693f0c9527c6373d31fae7e711f9270.zip | |
ecp5: Add support for flipflops with preload
Signed-off-by: David Shah <dave@ds0.me>
Diffstat (limited to 'ecp5/cells.cc')
| -rw-r--r-- | ecp5/cells.cc | 18 |
1 files changed, 15 insertions, 3 deletions
diff --git a/ecp5/cells.cc b/ecp5/cells.cc index 9accdd55..b06350c7 100644 --- a/ecp5/cells.cc +++ b/ecp5/cells.cc @@ -243,6 +243,7 @@ void ff_to_slice(Context *ctx, CellInfo *ff, CellInfo *lc, int index, bool drive lc->params[ctx->id(reg + "_SD")] = std::string(driven_by_lut ? "1" : "0"); lc->params[ctx->id(reg + "_REGSET")] = str_or_default(ff->params, ctx->id("REGSET"), "RESET"); + lc->params[ctx->id(reg + "_LSRMODE")] = str_or_default(ff->params, ctx->id("LSRMODE"), "LSR"); replace_port_safe(has_ff, ff, ctx->id("CLK"), lc, ctx->id("CLK")); if (ff->ports.find(ctx->id("LSR")) != ff->ports.end()) replace_port_safe(has_ff, ff, ctx->id("LSR"), lc, ctx->id("LSR")); @@ -250,10 +251,21 @@ void ff_to_slice(Context *ctx, CellInfo *ff, CellInfo *lc, int index, bool drive replace_port_safe(has_ff, ff, ctx->id("CE"), lc, ctx->id("CE")); replace_port(ff, ctx->id("Q"), lc, ctx->id("Q" + std::to_string(index))); - if (driven_by_lut) { - replace_port(ff, ctx->id("DI"), lc, ctx->id("DI" + std::to_string(index))); + if (get_net_or_empty(ff, ctx->id("M")) != nullptr) { + // PRLD FFs that use both M and DI + NPNR_ASSERT(!driven_by_lut); + // As M is used; must route DI through a new LUT + lc->params[ctx->id(reg + "_SD")] = std::string("1"); + lc->params[ctx->id("LUT" + std::to_string(index) + "_INITVAL")] = Property(0xFF00, 16); + replace_port(ff, ctx->id("DI"), lc, ctx->id("D" + std::to_string(index))); + replace_port(ff, ctx->id("M"), lc, ctx->id("M" + std::to_string(index))); + connect_ports(ctx, lc, ctx->id("F" + std::to_string(index)), lc, ctx->id("DI" + std::to_string(index))); } else { - replace_port(ff, ctx->id("DI"), lc, ctx->id("M" + std::to_string(index))); + if (driven_by_lut) { + replace_port(ff, ctx->id("DI"), lc, ctx->id("DI" + std::to_string(index))); + } else { + replace_port(ff, ctx->id("DI"), lc, ctx->id("M" + std::to_string(index))); + } } } |