sim -vcd: add date, version, and option for timescale

diff --git a/passes/sat/sim.cc b/passes/sat/sim.cc
index fb496ff87c3074a83d0a073622aa4ab7349c0203..4c9af0bf6a5c55ed2ba5666d6d21b357f3b9e0de 100644 (file)
--- a/passes/sat/sim.cc
+++ b/passes/sat/sim.cc
@@ -633,6 +633,7 @@ struct SimWorker : SimShared
        SimInstance *top = nullptr;
        std::ofstream vcdfile;
        pool<IdString> clock, clockn, reset, resetn;
+       std::string timescale;
 
        ~SimWorker()
        {
@@ -644,6 +645,15 @@ struct SimWorker : SimShared
                if (!vcdfile.is_open())
                        return;
 
+               vcdfile << stringf("$version %s $end\n", yosys_version_str);
+               vcdfile << stringf("$date ");
+               std::time_t t = std::time(nullptr);
+               vcdfile << std::put_time(std::localtime(&t), "%c %Z");
+               vcdfile << stringf(" $end\n");
+
+               if (!timescale.empty())
+                       vcdfile << stringf("$timescale %s $end\n", timescale.c_str());
+
                int id = 1;
                top->write_vcd_header(vcdfile, id);
 
@@ -783,6 +793,9 @@ struct SimPass : public Pass {
                log("    -zinit\n");
                log("        zero-initialize all uninitialized regs and memories\n");
                log("\n");
+               log("    -timescale <string>\n");
+               log("        include the specified timescale declaration in the vcd\n");
+               log("\n");
                log("    -n <integer>\n");
                log("        number of cycles to simulate (default: 20)\n");
                log("\n");
@@ -833,6 +846,10 @@ struct SimPass : public Pass {
                                worker.resetn.insert(RTLIL::escape_id(args[++argidx]));
                                continue;
                        }
+                       if (args[argidx] == "-timescale" && argidx+1 < args.size()) {
+                               worker.timescale = args[++argidx];
+                               continue;
+                       }
                        if (args[argidx] == "-a") {
                                worker.hide_internal = false;
                                continue;