boilerplate for external interrupts

Signed-off-by: Alfred Persson Forsberg <cat@catcream.org>

bench/servant_timer_tb.cpp

@@ -0,0 +1,92 @@
+#include <fcntl.h>
+#include <stdint.h>
+#include <signal.h>
+
+#include "verilated_vcd_c.h"
+#include "Vservant_timer_sim.h"
+
+#include <ctime>
+
+using namespace std;
+
+static bool done;
+
+vluint64_t main_time = 0;       // Current simulation time
+// This is a 64-bit integer to reduce wrap over issues and
+// allow modulus.  You can also use a double, if you wish.
+
+double sc_time_stamp () {       // Called by $time in Verilog
+  return main_time;           // converts to double, to match
+  // what SystemC does
+}
+
+void INThandler(int signal)
+{
+  printf("\nCaught ctrl-c\n");
+  done = true;
+}
+
+int main(int argc, char **argv, char **env)
+{
+  int baud_rate = 0;
+
+  Verilated::commandArgs(argc, argv);
+
+  Vservant_timer_sim* top = new Vservant_timer_sim;
+
+  VerilatedVcdC * tfp = 0;
+  const char *vcd = Verilated::commandArgsPlusMatch("vcd=");
+  if (vcd[0]) {
+    Verilated::traceEverOn(true);
+    tfp = new VerilatedVcdC;
+    top->trace (tfp, 99);
+    tfp->open ("trace.vcd");
+  }
+
+  signal(SIGINT, INThandler);
+
+  vluint64_t timeout = 0;
+  const char *arg_timeout = Verilated::commandArgsPlusMatch("timeout=");
+  if (arg_timeout[0])
+    timeout = atoi(arg_timeout+9);
+
+  vluint64_t vcd_start = 0;
+  const char *arg_vcd_start = Verilated::commandArgsPlusMatch("vcd_start=");
+  if (arg_vcd_start[0])
+    vcd_start = atoi(arg_vcd_start+11);
+
+  int cur_cycle = 0;
+  int last_cycle = 0;
+  std::time_t last_time = std::time(nullptr);
+
+  top->wb_clk = 0;
+  top->timer_clk = 0;
+  bool q = top->q;
+  int clock = 0;
+  top->eval();
+  while (!(done || Verilated::gotFinish())) {
+    top->eval();
+    if (top->wb_clk) {
+      clock++;
+    }
+    top->wb_rst = main_time < 1000;
+    if (tfp) {
+      tfp->dump(main_time);
+    }
+    if (top->wb_clk && top->pc_vld && top->pc_adr) {
+      std::this_thread::sleep_for(std::chrono::milliseconds(500));
+      printf("%d | %d\n", clock, top->pc_adr);
+    }
+    if (timeout && (main_time >= timeout)) {
+      printf("Timeout: Exiting at time %lu\n", main_time);
+      done = true;
+    }
+    top->wb_clk = !top->wb_clk;
+    top->timer_clk = top->wb_clk;
+    main_time+=31.25;
+  }
+  if (tfp) {
+    tfp->close();
+  }
+  exit(0);
+}