coolrunner2: Initial fixes for special p-terms

Certain signals can only be controlled by a product term and not a
sum-of-products. Do the initial work for fixing this.

diff --git a/techlibs/coolrunner2/coolrunner2_sop.cc b/techlibs/coolrunner2/coolrunner2_sop.cc
index 2d3961ee534650fc40c68741af737c1a4684a677..d526f8036baa5503d6d9a4f42b7b30092d68126b 100644 (file)
--- a/techlibs/coolrunner2/coolrunner2_sop.cc
+++ b/techlibs/coolrunner2/coolrunner2_sop.cc
@@ -55,6 +55,35 @@ struct Coolrunner2SopPass : public Pass {
                                }
                        }
 
+                       // Find wires that need to become special product terms
+                       dict<SigBit, pool<tuple<Cell*, std::string>>> special_pterms_no_inv;
+                       dict<SigBit, pool<tuple<Cell*, std::string>>> special_pterms_inv;
+                       for (auto cell : module->selected_cells())
+                       {
+                               if (cell->type == "\\FDCP" || cell->type == "\\FDCP_N" || cell->type == "\\FDDCP" ||
+                                       cell->type == "\\FTCP" || cell->type == "\\FTCP_N" || cell->type == "\\FTDCP" ||
+                                       cell->type == "\\FDCPE" || cell->type == "\\FDCPE_N" || cell->type == "\\FDDCPE" ||
+                                       cell->type == "\\LDCP" || cell->type == "\\LDCP_N")
+                               {
+                                       if (cell->hasPort("\\PRE"))
+                                               special_pterms_no_inv[sigmap(cell->getPort("\\PRE")[0])].insert(
+                                                       tuple<Cell*, const char *>(cell, "\\PRE"));
+                                       if (cell->hasPort("\\CLR"))
+                                               special_pterms_no_inv[sigmap(cell->getPort("\\CLR")[0])].insert(
+                                                       tuple<Cell*, const char *>(cell, "\\PRE"));
+                                       if (cell->hasPort("\\CE"))
+                                               special_pterms_no_inv[sigmap(cell->getPort("\\CE")[0])].insert(
+                                                       tuple<Cell*, const char *>(cell, "\\PRE"));
+
+                                       if (cell->hasPort("\\C"))
+                                               special_pterms_inv[sigmap(cell->getPort("\\C")[0])].insert(
+                                                       tuple<Cell*, const char *>(cell, "\\PRE"));
+                                       if (cell->hasPort("\\G"))
+                                               special_pterms_inv[sigmap(cell->getPort("\\G")[0])].insert(
+                                                       tuple<Cell*, const char *>(cell, "\\PRE"));
+                               }
+                       }
+
                        // Process $sop cells
                        for (auto cell : module->selected_cells())
                        {
@@ -80,6 +109,16 @@ struct Coolrunner2SopPass : public Pass {
                                                cells_to_remove.insert(std::get<1>(not_cell));
                                        }
 
+                                       // Check for special P-term usage
+                                       bool is_special_pterm = false;
+                                       bool special_pterm_can_invert = false;
+                                       if (special_pterms_no_inv.count(sop_output) || special_pterms_inv.count(sop_output))
+                                       {
+                                               is_special_pterm = true;
+                                               if (!special_pterms_no_inv.count(sop_output))
+                                                       special_pterm_can_invert = true;
+                                       }
+
                                        // Construct AND cells
                                        pool<SigBit> intermed_wires;
                                        for (int i = 0; i < sop_depth; i++) {
@@ -118,6 +157,40 @@ struct Coolrunner2SopPass : public Pass {
                                                xor_cell->setParam("\\INVERT_OUT", has_invert);
                                                xor_cell->setPort("\\IN_PTC", *intermed_wires.begin());
                                                xor_cell->setPort("\\OUT", sop_output);
+
+                                               // Special P-term handling
+                                               if (is_special_pterm)
+                                               {
+                                                       if (!has_invert)
+                                                       {
+                                                               // Can connect the P-term directly to the special term sinks
+                                                               for (auto x : special_pterms_inv[sop_output]) {
+                                                                       log("%s %s", std::get<0>(x)->name.c_str(), std::get<1>(x).c_str());
+                                                                       std::get<0>(x)->setPort(std::get<1>(x), *intermed_wires.begin());
+                                                               }
+                                                               for (auto x : special_pterms_no_inv[sop_output]) {
+                                                                       log("%s %s", std::get<0>(x)->name.c_str(), std::get<1>(x).c_str());
+                                                                       std::get<0>(x)->setPort(std::get<1>(x), *intermed_wires.begin());
+                                                               }
+                                                       }
+                                                       else
+                                                       {
+                                                               if (special_pterm_can_invert)
+                                                               {
+                                                                       log_assert(special_pterms_no_inv.count(sop_output) == 0);
+
+                                                                       // XXX TODO
+                                                                       log_assert(!"not implemented yet");
+                                                               }
+                                                               else
+                                                               {
+                                                                       // Need to construct a set of feed-through terms
+
+                                                                       // XXX TODO
+                                                                       log_assert(!"not implemented yet");
+                                                               }
+                                                       }
+                                               }
                                        }
                                        else
                                        {
@@ -135,6 +208,11 @@ struct Coolrunner2SopPass : public Pass {
                                                xor_cell->setParam("\\INVERT_OUT", has_invert);
                                                xor_cell->setPort("\\IN_ORTERM", or_to_xor_wire);
                                                xor_cell->setPort("\\OUT", sop_output);
+
+                                               if (is_special_pterm)
+                                               {
+                                                       // Need to construct a set of feed-through terms
+                                               }
                                        }
 
                                        // Finally, remove the $sop cell

diff --git a/techlibs/coolrunner2/synth_coolrunner2.cc b/techlibs/coolrunner2/synth_coolrunner2.cc
index fa7d9ac78cd668fa04db98d6fe8ffd2aa49e4e0f..562cce46088c02c7726dd74d0e3f569c6b1dba6f 100644 (file)
--- a/techlibs/coolrunner2/synth_coolrunner2.cc
+++ b/techlibs/coolrunner2/synth_coolrunner2.cc
@@ -152,7 +152,7 @@ struct SynthCoolrunner2Pass : public ScriptPass
                if (check_label("map_pla"))
                {
                        run("abc -sop -I 40 -P 56");
-                       run("coolrunner2_sop");
+                       run("clean");
                }
 
                if (check_label("map_cells"))
@@ -162,7 +162,9 @@ struct SynthCoolrunner2Pass : public ScriptPass
                        run("dffinit -ff FDCP_N Q INIT");
                        run("dffinit -ff LDCP Q INIT");
                        run("dffinit -ff LDCP_N Q INIT");
+                       run("coolrunner2_sop");
                        run("iopadmap -bits -inpad IBUF O:I -outpad IOBUFE I:IO -inoutpad IOBUFE O:IO -toutpad IOBUFE E:I:IO -tinoutpad IOBUFE E:O:I:IO");
+                       run("clean");
                }
 
                if (check_label("check"))