diff options
Diffstat (limited to 'passes/techmap/shregmap.cc')
| -rw-r--r-- | passes/techmap/shregmap.cc | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/passes/techmap/shregmap.cc b/passes/techmap/shregmap.cc index a541b33be..21dfe9619 100644 --- a/passes/techmap/shregmap.cc +++ b/passes/techmap/shregmap.cc @@ -178,7 +178,17 @@ struct ShregmapTechXilinx7 : ShregmapTech // Only map if $shiftx exclusively covers the shift register if (shiftx->type == "$shiftx") { - if (GetSize(taps) != shiftx->getParam("\\A_WIDTH").as_int()) + if (GetSize(taps) > shiftx->getParam("\\A_WIDTH").as_int()) + return false; + // Due to padding the most significant bits of A may be 1'bx, + // and if so, discount them + if (GetSize(taps) < shiftx->getParam("\\A_WIDTH").as_int()) { + const SigSpec A = shiftx->getPort("\\A"); + const int A_width = shiftx->getParam("\\A_WIDTH").as_int(); + for (int i = GetSize(taps); i < A_width; ++i) + if (A[i] != RTLIL::Sx) return false; + } + else if (GetSize(taps) != shiftx->getParam("\\A_WIDTH").as_int()) return false; } else if (shiftx->type == "$mux") { @@ -596,6 +606,9 @@ struct ShregmapPass : public Pass { log(" -tech greenpak4\n"); log(" map to greenpak4 shift registers.\n"); log("\n"); + log(" -tech xilinx\n"); + log(" map to xilinx dynamic-length shift registers.\n"); + log("\n"); } void execute(std::vector<std::string> args, RTLIL::Design *design) YS_OVERRIDE { |