diff --git a/src/test/csrc/verilator/emu.cpp b/src/test/csrc/verilator/emu.cpp
index 675b66906..f564f0ac1 100644
--- a/src/test/csrc/verilator/emu.cpp
+++ b/src/test/csrc/verilator/emu.cpp
@@ -98,7 +98,6 @@ static inline void print_help(const char *file) {
 #endif
   printf("      --flash                the flash bin file for simulation\n");
   printf("      --sim-run-ahead        let a fork of simulator run ahead of commit for perf analysis\n");
-  printf("      --ref-trace            print reference trace\n");
   printf("      --wave-path=FILE       dump waveform to a specified PATH\n");
   printf("      --ram-size=SIZE        simulation memory size, for example 8GB / 128MB\n");
   printf("      --enable-fork          enable folking child processes to debug\n");
@@ -135,7 +134,6 @@ inline EmuArgs parse_args(int argc, const char *argv[]) {
     { "wave-path",         1, NULL,  0  },
     { "ram-size",          1, NULL,  0  },
     { "sim-run-ahead",     0, NULL,  0  },
-    { "ref-trace",         0, NULL,  0  },
     { "dump-db",           0, NULL,  0  },
     { "dump-select-db",    1, NULL,  0  },
     { "dump-coverage",     0, NULL,  0  },
@@ -192,35 +190,34 @@ inline EmuArgs parse_args(int argc, const char *argv[]) {
             printf("[WARN] runahead is not enabled at compile time, ignore --sim-run-ahead\n");
 #endif
             continue;
-          case 11: args.enable_ref_trace = true; continue;
 #ifdef ENABLE_CHISEL_DB
-          case 12: args.dump_db = true; continue;
-          case 13:
+          case 11: args.dump_db = true; continue;
+          case 12:
             args.dump_db = true;
             args.select_db = optarg;
             continue;
 #else
+          case 11:
           case 12:
-          case 13:
             printf("[WARN] chisel db is not enabled at compile time, ignore --dump-db\n");
             continue;
 #endif
-          case 14:
+          case 13:
 #if VM_COVERAGE == 1
             args.dump_coverage = true;
 #else
             printf("[WARN] coverage is not enabled at compile time, ignore --dump-coverage\n");
 #endif // VM_COVERAGE
             continue;
-          case 15: args.enable_ref_trace = true; continue;
-          case 16: args.enable_commit_trace = true; continue;
-          case 17: args.trace_name = optarg; args.trace_is_read = true; continue;
-          case 18: args.trace_name = optarg; args.trace_is_read = false; continue;
-          case 19: args.footprints_name = optarg; continue;
-          case 20: args.image_as_footprints = true; continue;
-          case 21: args.linearized_name = optarg; continue;
-          case 22: args.enable_waveform = true; args.enable_waveform_full = true; continue;
-          case 23: args.overwrite_nbytes = atoll_strict(optarg, "overwrite_nbytes"); continue;
+          case 14: args.enable_ref_trace = true; continue;
+          case 15: args.enable_commit_trace = true; continue;
+          case 16: args.trace_name = optarg; args.trace_is_read = true; continue;
+          case 17: args.trace_name = optarg; args.trace_is_read = false; continue;
+          case 18: args.footprints_name = optarg; continue;
+          case 19: args.image_as_footprints = true; continue;
+          case 20: args.linearized_name = optarg; continue;
+          case 21: args.enable_waveform = true; args.enable_waveform_full = true; continue;
+          case 22: args.overwrite_nbytes = atoll_strict(optarg, "overwrite_nbytes"); continue;
         }
         // fall through
       default:
@@ -661,18 +658,6 @@ int Emulator::tick() {
   }
 #endif
 
-#ifndef CONFIG_NO_DIFFTEST
-  // if ref trace is enabled in co-sim args
-  // let simulator print debug info
-  if (args.enable_ref_trace) {
-    RefProxyConfig ref_config;
-    ref_config.debug_difftest = true;
-    for (int i = 0; i < NUM_CORES; i++) {
-      difftest[i]->proxy->update_config(&ref_config);
-    }
-  }
-#endif // CONFIG_NO_DIFFTEST
-
   if (args.enable_fork && is_fork_child() && cycles != 0) {
     if (cycles == lightsss->get_end_cycles()) {
       FORK_PRINTF("checkpoint has reached the main process abort point: %lu\n", cycles)