diff --git a/src/main/resources/csrc/SimMemTrace.cc b/src/main/resources/csrc/SimMemTrace.cc
index 61096cd..7cc2f8a 100644
--- a/src/main/resources/csrc/SimMemTrace.cc
+++ b/src/main/resources/csrc/SimMemTrace.cc
@@ -1,22 +1,72 @@
 #include <vpi_user.h>
 #include <svdpi.h>
+#include <memory>
+#include <string>
+#include <fstream>
+#include <cstdio>
+#include <unistd.h>
 
-#include <stdio.h>
-#include <string.h>
+class MemTraceReader;
+static std::unique_ptr<MemTraceReader> reader;
 
-extern "C" void memtrace_init(
-        const char *filename)
-{
-    printf("memtrace_init: filename=[%s]\n", filename);
+class MemTraceReader {
+public:
+  MemTraceReader(const std::string &filename) {
+    char cwd[4096];
+    if (getcwd(cwd, sizeof(cwd))) {
+        printf("MemTraceReader: current working dir: %s\n", cwd);
+    }
+
+    infile.open(filename);
+    if (infile.fail()) {
+        fprintf(stderr, "failed to open file %s\n", filename);
+    }
+  }
+  ~MemTraceReader() {
+    infile.close();
+    printf("MemTraceReader destroyed\n");
+  }
+  bool tick();
+
+  std::ifstream infile;
+};
+
+// Returns true if there is no more memory trace left to read.
+bool MemTraceReader::tick() {
+  std::string line;
+  long cycle = 0;
+  char loadstore[10]{0};
+  int core_id = 0;
+  int thread_id = 0;
+  unsigned long address = 0;
+  unsigned long data = 0;
+  int data_size = 0;
+
+  if (!(infile >> cycle >> loadstore >> core_id >> thread_id
+        >> std::hex >>
+        address >> data >> std::dec >> data_size
+        )) {
+    return true;
+  }
+
+  printf("cycle: %ld\n", cycle);
+  return false;
 }
 
-extern "C" void memtrace_tick(
-        unsigned char *trace_read_valid,
-        unsigned char trace_read_ready,
-        char *trace_read_bits)
-{
-    printf("tick!\n");
+extern "C" void memtrace_init(const char *filename) {
+  reader = std::make_unique<MemTraceReader>(filename);
+  printf("memtrace_init: filename=[%s]\n", filename);
+}
+
+extern "C" void memtrace_tick(unsigned char *trace_read_valid,
+                              unsigned char trace_read_ready,
+                              char *trace_read_bits) {
+  *trace_read_bits = 42;
+
+  *trace_read_valid = 0;
+  if (reader->tick()) {
     *trace_read_valid = 1;
-    *trace_read_bits = 42;
-    return;
+  }
+
+  return;
 }
diff --git a/src/main/resources/vsrc/SimMemTrace.v b/src/main/resources/vsrc/SimMemTrace.v
index 99b8b1f..8c1a161 100644
--- a/src/main/resources/vsrc/SimMemTrace.v
+++ b/src/main/resources/vsrc/SimMemTrace.v
@@ -27,7 +27,7 @@ module SimMemTrace  (
 
     initial begin
         $value$plusargs("uartlog=%s", __uartlog);
-        memtrace_init(__uartlog);
+        memtrace_init("vecadd.core1.thread4.trace");
     end
 
     reg __in_valid_reg;