nexus: Miscellaneous DSP infrastructure

Signed-off-by: David Shah <dave@ds0.me>

4 files changed, 135 insertions, 24 deletions

diff --git a/common/design_utils.cc b/common/design_utils.cc
index 7f339bac..5227585f 100644
--- a/common/design_utils.cc
+++ b/common/design_utils.cc
@@ -164,25 +164,13 @@ void rename_net(Context *ctx, NetInfo *net, IdString new_name)
     net->name = new_name;
 }
 
-std::vector<NetInfo *> create_bus(Context *ctx, IdString base_name, const std::string &postfix, int width)
+void replace_bus(Context *ctx, CellInfo *old_cell, IdString old_name, int old_offset, CellInfo *new_cell,
+                 IdString new_name, int new_offset, int width, bool square_brackets)
 {
-    std::vector<NetInfo *> nets;
-    for (int i = 0; i < width; i++)
-        nets.push_back(ctx->createNet(ctx->id(stringf("%s/%s[%d]", base_name.c_str(ctx), postfix.c_str(), i))));
-    return nets;
-}
-
-void connect_bus(Context *ctx, CellInfo *cell, IdString port, std::vector<NetInfo *> &bus, PortType dir)
-{
-    for (int i = 0; i < int(bus.size()); i++) {
-        IdString p = ctx->id(stringf("%s%d", port.c_str(ctx), i));
-        if (!cell->ports.count(p)) {
-            cell->ports[p].name = p;
-            cell->ports[p].type = dir;
-        } else {
-            NPNR_ASSERT(cell->ports.at(p).type == dir);
-        }
-        connect_port(ctx, bus.at(i), cell, p);
+    for (int i = 0; i < width; i++) {
+        IdString old_port = ctx->id(stringf(square_brackets ? "%s[%d]" : "%s%d", old_name.c_str(ctx), i + old_offset));
+        IdString new_port = ctx->id(stringf(square_brackets ? "%s[%d]" : "%s%d", new_name.c_str(ctx), i + new_offset));
+        replace_port(old_cell, old_port, new_cell, new_port);
     }
 }
 
diff --git a/common/design_utils.h b/common/design_utils.h
index 3a2245a7..2014e7ad 100644
--- a/common/design_utils.h
+++ b/common/design_utils.h
@@ -104,14 +104,12 @@ void rename_port(Context *ctx, CellInfo *cell, IdString old_name, IdString new_n
 // Rename a net without invalidating pointers to it
 void rename_net(Context *ctx, NetInfo *net, IdString new_name);
 
-// Create a bus of nets
-std::vector<NetInfo *> create_bus(Context *ctx, IdString base_name, const std::string &postfix, int width);
-
-// Connect a bus of nets to a bus of ports
-void connect_bus(Context *ctx, CellInfo *cell, IdString port, std::vector<NetInfo *> &bus, PortType dir);
-
 void print_utilisation(const Context *ctx);
 
+// Disconnect a bus of nets (if connected) from old, and connect it to the new ports
+void replace_bus(Context *ctx, CellInfo *old_cell, IdString old_name, int old_offset, CellInfo *new_cell,
+                 IdString new_name, int new_offset, int new_width, bool square_brackets = true);
+
 NEXTPNR_NAMESPACE_END
 
 #endif
diff --git a/nexus/constids.inc b/nexus/constids.inc
index a43104e2..a996f0f8 100644
--- a/nexus/constids.inc
+++ b/nexus/constids.inc
@@ -165,6 +165,16 @@ X(MULT18X36_CORE)
 X(MULT36_CORE)
 X(ACC54_CORE)
 
+X(PREADD9)
+X(MULT9)
+X(MULT18)
+X(REG18)
+X(M18X36)
+X(MULT36)
+X(ACC54)
+
+X(MULT9X9)
+
 X(DCC)
 X(CLKI)
 X(CLKO)
@@ -215,3 +225,70 @@ X(DWS4)
 X(WEAMUX)
 
 X(VCC_DRV)
+
+X(RSTCL)
+X(CECL)
+X(B2)
+X(B3)
+X(B4)
+X(B5)
+X(B6)
+X(B7)
+X(B8)
+X(BSIGNED)
+X(C2)
+X(C3)
+X(C4)
+X(C5)
+X(C6)
+X(C7)
+X(C8)
+X(C9)
+
+X(RSTP)
+X(CEP)
+X(A2)
+X(A3)
+X(A4)
+X(A5)
+X(A6)
+X(A7)
+X(A8)
+X(ASIGNED)
+
+X(SFTCTRL0)
+X(SFTCTRL1)
+X(SFTCTRL2)
+X(SFTCTRL3)
+X(ROUNDEN)
+
+X(LOAD)
+X(M9ADDSUB1)
+X(M9ADDSUB0)
+X(ADDSUB1)
+X(ADDSUB0)
+
+X(CEO)
+X(RSTO)
+X(CEC)
+X(RSTC)
+X(SIGNEDI)
+X(CECIN)
+X(CECTRL)
+X(RSTCIN)
+X(RSTCTRL)
+
+X(SIGNEDSTATIC_EN)
+X(SUBSTRACT_EN)
+X(CSIGNED)
+X(BSIGNED_OPERAND_EN)
+X(BYPASS_PREADD9)
+X(REGBYPSBR0)
+X(REGBYPSBR1)
+X(REGBYPSBL)
+X(SHIFTBR)
+X(SHIFTBL)
+X(PREADDCAS_EN)
+X(SR_18BITSHIFT_EN)
+X(OPC)
+X(RESET)
diff --git a/nexus/pack.cc b/nexus/pack.cc
index 50278d48..d39a1c89 100644
--- a/nexus/pack.cc
+++ b/nexus/pack.cc
@@ -1351,6 +1351,54 @@ struct NexusPacker
             auto_cascade_cell(child, cell2bel.at(child->name), bel2cell);
     }
 
+    // Create a DSP cell
+    CellInfo *create_dsp_cell(IdString base_name, IdString type, CellInfo *constr_base, int dx, int dz)
+    {
+        IdString name = ctx->id(stringf("%s/%s_x%d_z%d", ctx->nameOf(base_name), ctx->nameOf(type), dx, dz));
+        CellInfo *cell = ctx->createCell(name, type);
+        if (constr_base != nullptr) {
+            // We might be constraining against an already-constrained cell
+            if (constr_base->constr_parent != nullptr) {
+                cell->constr_x = dx + constr_base->constr_x;
+                cell->constr_y = constr_base->constr_y;
+                cell->constr_z = dz + constr_base->constr_z;
+                cell->constr_abs_z = false;
+                cell->constr_parent = constr_base->constr_parent;
+                constr_base->constr_parent->constr_children.push_back(cell);
+            } else {
+                cell->constr_x = dx;
+                cell->constr_y = 0;
+                cell->constr_z = dz;
+                cell->constr_abs_z = false;
+                cell->constr_parent = constr_base;
+                constr_base->constr_children.push_back(cell);
+            }
+        }
+        // Setup some default parameters
+        if (type == id_PREADD9_CORE) {
+            cell->params[id_SIGNEDSTATIC_EN] = std::string("DISABLED");
+            cell->params[id_BYPASS_PREADD9] = std::string("BYPASS");
+            cell->params[id_CSIGNED] = std::string("DISABLED");
+            cell->params[id_GSR] = std::string("DISABLED");
+            cell->params[id_OPC] = std::string("INPUT_B_AS_PREADDER_OPERAND");
+            cell->params[id_PREADDCAS_EN] = std::string("DISABLED");
+            cell->params[id_PREADDCAS_EN] = std::string("DISABLED");
+            cell->params[id_PREADDCAS_EN] = std::string("DISABLED");
+            cell->params[id_REGBYPSBL] = std::string("REGISTER");
+            cell->params[id_REGBYPSBR0] = std::string("BYPASS");
+            cell->params[id_REGBYPSBR1] = std::string("BYPASS");
+            cell->params[id_RESET] = std::string("SYNC");
+            cell->params[id_SHIFTBL] = std::string("BYPASS");
+            cell->params[id_SHIFTBR] = std::string("REGISTER");
+            cell->params[id_SIGNEDSTATIC_EN] = std::string("DISABLED");
+            cell->params[id_SR_18BITSHIFT_EN] = std::string("DISABLED");
+            cell->params[id_SUBSTRACT_EN] = std::string("SUBTRACTION");
+        }
+        return cell;
+    }
+
+    void pack_dsps() { log_info("Packing DSPs...\n"); }
+
     explicit NexusPacker(Context *ctx) : ctx(ctx) {}
 
     void operator()()