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-rw-r--r--fpga_interchange/arch.cc53
1 files changed, 53 insertions, 0 deletions
diff --git a/fpga_interchange/arch.cc b/fpga_interchange/arch.cc
index c1446245..441c2e1f 100644
--- a/fpga_interchange/arch.cc
+++ b/fpga_interchange/arch.cc
@@ -727,6 +727,7 @@ bool Arch::pack()
decode_lut_cells();
merge_constant_nets();
pack_ports();
+ pack_default_conns();
return true;
}
@@ -1984,6 +1985,58 @@ DelayQuad Arch::getPipDelay(PipId pip) const
return DelayQuad(100 * (1 + pip_data.pseudo_cell_wires.size()));
}
+const DefaultCellConnsPOD *Arch::get_default_conns(IdString cell_type) const
+{
+ for (const auto &conn : chip_info->constants->default_conns) {
+ if (IdString(conn.cell_type) == cell_type)
+ return &conn;
+ }
+ return nullptr;
+}
+
+void Arch::pack_default_conns()
+{
+ IdString vcc_net_name(chip_info->constants->vcc_net_name);
+ IdString gnd_net_name(chip_info->constants->gnd_net_name);
+ Context *ctx = getCtx();
+
+ std::vector<IdString> dead_nets;
+
+ for (auto cell : sorted(ctx->cells)) {
+ CellInfo *ci = cell.second;
+ const DefaultCellConnsPOD *conns = get_default_conns(ci->type);
+ if (conns == nullptr)
+ continue;
+ for (const auto &pin : conns->pins) {
+ IdString pin_name(pin.pin_name);
+ // pin missing, create it
+ if (!ci->ports.count(pin_name))
+ ci->addInput(pin_name);
+ const NetInfo *net = ci->ports.at(pin_name).net;
+ if (net != nullptr) {
+ // pin is connected, and driven, nothing to do
+ if (net->driver.cell != nullptr)
+ continue;
+ // pin is connected but undriven, disconnect the existing net
+ ctx->disconnectPort(ci->name, pin_name);
+ // remove net if it has no remaining users
+ if (net->users.empty())
+ dead_nets.push_back(net->name);
+ }
+ if (pin.value == PIN_VALUE_GND)
+ ctx->connectPort(gnd_net_name, ci->name, pin_name);
+ else if (pin.value == PIN_VALUE_VCC)
+ ctx->connectPort(vcc_net_name, ci->name, pin_name);
+ else
+ NPNR_ASSERT(pin.value == PIN_VALUE_FLOAT);
+ }
+ }
+
+ // Remove any left-behind nets with no users and no drivers
+ for (auto net : dead_nets)
+ ctx->nets.erase(net);
+}
+
// Instance constraint templates.
template void Arch::ArchConstraints::bindBel(Arch::ArchConstraints::TagState *, const Arch::ConstraintRange);
template void Arch::ArchConstraints::unbindBel(Arch::ArchConstraints::TagState *, const Arch::ConstraintRange);