Merge pull request #2403 from nakengelhardt/sim_timescale

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

passes/sat/sim.cc

@@ -22,6 +22,8 @@
 #include "kernel/celltypes.h"
 #include "kernel/mem.h"
 
+#include <ctime>
+
 USING_YOSYS_NAMESPACE
 PRIVATE_NAMESPACE_BEGIN
 
@@ -620,6 +622,7 @@ struct SimWorker : SimShared
 	SimInstance *top = nullptr;
 	std::ofstream vcdfile;
 	pool<IdString> clock, clockn, reset, resetn;
+	std::string timescale;
 
 	~SimWorker()
 	{
@@ -631,6 +634,17 @@ struct SimWorker : SimShared
 		if (!vcdfile.is_open())
 			return;
 
+		vcdfile << stringf("$version %s $end\n", yosys_version_str);
+
+		std::time_t t = std::time(nullptr);
+		char mbstr[255];
+		if (std::strftime(mbstr, sizeof(mbstr), "%c", std::localtime(&t))) {
+			vcdfile << stringf("$date ") << mbstr << stringf(" $end\n");
+		}
+
+		if (!timescale.empty())
+			vcdfile << stringf("$timescale %s $end\n", timescale.c_str());
+
 		int id = 1;
 		top->write_vcd_header(vcdfile, id);
 
@@ -770,6 +784,9 @@ 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");
@@ -820,6 +837,10 @@ 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;