Booth multiplier

1 files changed, 76 insertions, 0 deletions

diff --git a/sim.cpp b/sim.cpp
new file mode 100644
index 0000000..0b697ee
--- /dev/null
+++ b/sim.cpp
@@ -0,0 +1,76 @@
+#include <memory>
+#include <limits>
+#include <cstdint>
+#include <iostream>
+#include <verilated.h>
+#include "Vboothmul.h"
+
+using word = int16_t;
+using dword = int32_t;
+
+constexpr word minint = std::numeric_limits<word>::min();
+constexpr word maxint = std::numeric_limits<word>::max();
+
+uint32_t main_time = 0;
+
+double sc_time_stamp() {
+	return main_time;
+}
+
+Vboothmul *mod;
+
+static void run_clock() {
+	mod->clk = !mod->clk;
+	mod->eval();
+	main_time++;
+
+	mod->clk = !mod->clk;
+	mod->eval();
+	main_time++;
+}
+
+static void run(word i, word j) {
+	// Processor is twos-compliment
+	mod->a1 = i;
+	mod->a2 = j;
+	mod->arm = 1;
+
+	while (!mod->fin)
+		run_clock();
+
+	dword expected = (dword) i * (dword) j;
+	if (mod->outn != expected) {
+		std::cout << i << "*" << j << "=" << expected
+		          << "(" << mod->outn << ")" << std::endl;
+	}
+
+	mod->arm = 0;
+	run_clock();
+}
+
+int main(int argc, char **argv) {
+	Verilated::commandArgs(argc, argv);
+	// Verilated::traceEverOn(true);
+	mod = new Vboothmul;
+
+	mod->clk = 0;
+	mod->arm = 0;
+	run_clock();
+
+	run(minint, minint);
+	run(minint, maxint);
+	run(maxint, minint);
+	run(maxint, maxint);
+
+	for (word i = -20; i < 20; i++) {
+		for (word j = - 20; j < 20; j++) {
+			run(i, j);
+		}
+	}
+
+	mod->final();
+
+	delete mod;
+
+	return 0;
+}