diff --git a/himbaechel/uarch/ng-ultra/pack.cc b/himbaechel/uarch/ng-ultra/pack.cc
index 8769f1bb..45dcc0e6 100644
--- a/himbaechel/uarch/ng-ultra/pack.cc
+++ b/himbaechel/uarch/ng-ultra/pack.cc
@@ -475,38 +475,40 @@ void NgUltraPacker::pack_iobs(void)
         NetInfo *o_net = cell->getPort(id_O);
         if (o_net) {
             CellInfo *iod = net_only_drives(ctx, o_net, is_dfr, id_I, true);
-            bool bfr_mode = false;
-            if (!iod) {
-                if (cell->type==id_IOTP) ddrf_as_bfr++; else dfr_as_bfr++;
-                iod = create_cell_ptr((cell->type==id_IOTP) ? id_DDFR : id_DFR, ctx->id(cell->name.str(ctx) + "$iod_id"));
-                NetInfo *new_in = ctx->createNet(ctx->id(iod->name.str(ctx) + "$I"));
-                iod->setParam(ctx->id("iobname"),str_or_default(cell->params, ctx->id("iobname"), ""));
-                iod->setParam(ctx->id("type"), Property("BFR"));
-                cell->disconnectPort(id_O);
-                iod->connectPort(id_O, o_net);
-                iod->setParam(ctx->id("mode"), Property(2, 2));
-                iod->setParam(ctx->id("data_inv"), Property(0, 1));
-                iod->connectPort(id_I, new_in);
-                cell->connectPort(id_O,new_in);
-                bfr_mode = true;
-            } else log_error("TODO handle DFR");
-            Loc cd_loc = cell->getLocation();
-            cd_loc.z += 1;
-            BelId bel = ctx->getBelByLocation(cd_loc);
-            ctx->bindBel(bel, iod, PlaceStrength::STRENGTH_LOCKED);
+            if (!(o_net->users.entries()==1 && (*o_net->users.begin()).cell->type == id_NX_IOM_U)) {
+                bool bfr_mode = false;
+                if (!iod) {
+                    if (cell->type==id_IOTP) ddrf_as_bfr++; else dfr_as_bfr++;
+                    iod = create_cell_ptr((cell->type==id_IOTP) ? id_DDFR : id_DFR, ctx->id(cell->name.str(ctx) + "$iod_id"));
+                    NetInfo *new_in = ctx->createNet(ctx->id(iod->name.str(ctx) + "$I"));
+                    iod->setParam(ctx->id("iobname"),str_or_default(cell->params, ctx->id("iobname"), ""));
+                    iod->setParam(ctx->id("type"), Property("BFR"));
+                    cell->disconnectPort(id_O);
+                    iod->connectPort(id_O, o_net);
+                    iod->setParam(ctx->id("mode"), Property(2, 2));
+                    iod->setParam(ctx->id("data_inv"), Property(0, 1));
+                    iod->connectPort(id_I, new_in);
+                    cell->connectPort(id_O,new_in);
+                    bfr_mode = true;
+                } else log_error("TODO handle DFR");
+                Loc cd_loc = cell->getLocation();
+                cd_loc.z += 1;
+                BelId bel = ctx->getBelByLocation(cd_loc);
+                ctx->bindBel(bel, iod, PlaceStrength::STRENGTH_LOCKED);
 
-            // Depending of DDFR mode we must use one of dedicated routes (ITCs)
-            if (iod->type==id_DDFR) {
-                WireId dwire = ctx->getBelPinWire(bel, id_O);
-                for (PipId pip : ctx->getPipsDownhill(dwire)) {
-                    const auto &pip_data = chip_pip_info(ctx->chip_info, pip);
-                    const auto &extra_data = *reinterpret_cast<const NGUltraPipExtraDataPOD *>(pip_data.extra_data.get());
-                    if (!extra_data.name) continue;
-                    if (extra_data.type != PipExtra::PIP_EXTRA_MUX) continue;
-                    if (bfr_mode && extra_data.input == 2) {
-                        uarch->blocked_pips.emplace(pip);
-                    } else if (!bfr_mode && extra_data.input == 1) {
-                        uarch->blocked_pips.emplace(pip);
+                // Depending of DDFR mode we must use one of dedicated routes (ITCs)
+                if (iod->type==id_DDFR) {
+                    WireId dwire = ctx->getBelPinWire(bel, id_O);
+                    for (PipId pip : ctx->getPipsDownhill(dwire)) {
+                        const auto &pip_data = chip_pip_info(ctx->chip_info, pip);
+                        const auto &extra_data = *reinterpret_cast<const NGUltraPipExtraDataPOD *>(pip_data.extra_data.get());
+                        if (!extra_data.name) continue;
+                        if (extra_data.type != PipExtra::PIP_EXTRA_MUX) continue;
+                        if (bfr_mode && extra_data.input == 2) {
+                            uarch->blocked_pips.emplace(pip);
+                        } else if (!bfr_mode && extra_data.input == 1) {
+                            uarch->blocked_pips.emplace(pip);
+                        }
                     }
                 }
             }