diff options
Diffstat (limited to 'nexus/pack.cc')
| -rw-r--r-- | nexus/pack.cc | 17 |
1 files changed, 15 insertions, 2 deletions
diff --git a/nexus/pack.cc b/nexus/pack.cc index 0ef3eb79..386c5f4b 100644 --- a/nexus/pack.cc +++ b/nexus/pack.cc @@ -494,7 +494,7 @@ struct NexusPacker if (o == nullptr) ; else if (o->users.size() > 1) - log_error("Top level '%s' has multiple input buffers\n", ctx->nameOf(port.first)); + log_error("Top level pin '%s' has multiple input buffers\n", ctx->nameOf(port.first)); else if (o->users.size() == 1) top_port = o->users.at(0); } @@ -504,9 +504,22 @@ struct NexusPacker NetInfo *i = get_net_or_empty(ci, id_I); if (i != nullptr && i->driver.cell != nullptr) { if (top_port.cell != nullptr) - log_error("Top level '%s' has multiple input/output buffers\n", ctx->nameOf(port.first)); + log_error("Top level pin '%s' has multiple input/output buffers\n", ctx->nameOf(port.first)); top_port = i->driver; } + // Edge case of a bidirectional buffer driving an output pin + if (i->users.size() > 2) { + log_error("Top level pin '%s' has illegal buffer configuration\n", ctx->nameOf(port.first)); + } else if (i->users.size() == 2) { + if (top_port.cell != nullptr) + log_error("Top level pin '%s' has illegal buffer configuration\n", ctx->nameOf(port.first)); + for (auto &usr : i->users) { + if (usr.cell->type == ctx->id("$nextpnr_obuf") || usr.cell->type == ctx->id("$nextpnr_iobuf")) + continue; + top_port = usr; + break; + } + } } if (!is_npnr_iob) log_error("Port '%s' doesn't seem to have a corresponding top level IO (internal cell type mismatch)\n", |