Merge branch 'master' of gitlab.com:SymbioticEDA/nextpnr

2 files changed, 20 insertions, 5 deletions

diff --git a/ice40/cells.cc b/ice40/cells.cc
index b6f10f7b..582e5c14 100644
--- a/ice40/cells.cc
+++ b/ice40/cells.cc
@@ -210,6 +210,10 @@ void nxio_to_sb(Context *ctx, CellInfo *nxio, CellInfo *sbio)
         replace_port(tbuf, "A", sbio, "D_OUT_0");
         replace_port(tbuf, "E", sbio, "OUTPUT_ENABLE");
         ctx->nets.erase(donet->name);
+        if (!donet->users.empty())
+            log_error("unsupported tristate IO pattern for IO buffer '%s', "
+                      "instantiate SB_IO manually to ensure correct behaviour\n",
+                      nxio->name.c_str(ctx));
         ctx->cells.erase(tbuf->name);
     }
 }
diff --git a/ice40/pack.cc b/ice40/pack.cc
index 92f9a369..d3f07118 100644
--- a/ice40/pack.cc
+++ b/ice40/pack.cc
@@ -203,23 +203,33 @@ static void pack_constants(Context *ctx)
 
     std::vector<IdString> dead_nets;
 
+    bool gnd_used = false, vcc_used = false;
+
     for (auto net : ctx->nets) {
         NetInfo *ni = net.second;
         if (ni->driver.cell != nullptr &&
             ni->driver.cell->type == ctx->id("GND")) {
             set_net_constant(ctx, ni, gnd_net, false);
-            ctx->cells[gnd_cell->name] = gnd_cell;
-            ctx->nets[gnd_net->name] = gnd_net;
+            gnd_used = true;
             dead_nets.push_back(net.first);
         } else if (ni->driver.cell != nullptr &&
                    ni->driver.cell->type == ctx->id("VCC")) {
             set_net_constant(ctx, ni, vcc_net, true);
-            ctx->cells[vcc_cell->name] = vcc_cell;
-            ctx->nets[vcc_net->name] = vcc_net;
+            vcc_used = true;
             dead_nets.push_back(net.first);
         }
     }
 
+    if (gnd_used) {
+        ctx->cells[gnd_cell->name] = gnd_cell;
+        ctx->nets[gnd_net->name] = gnd_net;
+    }
+
+    if (vcc_used) {
+        ctx->cells[vcc_cell->name] = vcc_cell;
+        ctx->nets[vcc_net->name] = vcc_net;
+    }
+
     for (auto dn : dead_nets)
         ctx->nets.erase(dn);
 }
@@ -265,7 +275,8 @@ static void pack_io(Context *ctx)
                 }
             } else {
                 // Create a SB_IO buffer
-                sb = create_ice_cell(ctx, "SB_IO");
+                sb = create_ice_cell(ctx, "SB_IO",
+                                     ci->name.str(ctx) + "$sb_io");
                 nxio_to_sb(ctx, ci, sb);
                 new_cells.push_back(sb);
             }