diff --git a/regression/Makefile b/regression/Makefile
index 62c861d7..474bd60a 100644
--- a/regression/Makefile
+++ b/regression/Makefile
@@ -228,7 +228,7 @@ stamps/%/vsim-jtag-dtm-32-$(JTAG_DTM_TEST).stamp: stamps/%/vsim$(JTAG_STAMP_SUFF
 	--sim_cmd="$(abspath $(TOP))/vsim/simv-$(PROJECT)-$*$(JTAG_DEBUG_SUFFIX) +verbose $(VSIM_JTAG_VCDPLUS_32)" \
 	--server_cmd="$(RISCV)/bin/openocd $(OPENOCD_DEBUG) \
 	--s $(RISCV)/share/openocd/scripts" \
-	$(abspath $(TOP))/scripts/FreedomSim.py \
+	$(abspath $(TOP))/scripts/RocketSim.py \
 	$(JTAG_DTM_TEST)
 	date > $@
 
@@ -237,7 +237,7 @@ stamps/%/vsim-jtag-dtm-64-$(JTAG_DTM_TEST).stamp: stamps/%/vsim$(JTAG_STAMP_SUFF
 	--sim_cmdrun "$(abspath $(TOP))/vsim/simv-$(PROJECT)-$*$(JTAG_DEBUG_SUFFIX) +verbose $(VSIM_JTAG_VCDPLUS_64)" \
 	--server_cmd="$(OPENOCD_INSTALL)_$(OPENOCD_VERSION)/bin/openocd $(OPENOCD_DEBUG) \
 	--s $(OPENOCD_INSTALL)_$(OPENOCD_VERSION)/share/openocd/scripts" \
-	$(abspath $(TOP))/scripts/FreedomSim.py \
+	$(abspath $(TOP))/scripts/RocketSim.py \
 	$(JTAG_DTM_TEST)
 	date > $@
 
@@ -246,7 +246,7 @@ stamps/%/emulator-jtag-dtm-32-$(JTAG_DTM_TEST).stamp:  stamps/%/emulator$(JTAG_S
 	--sim_cmd "$(abspath $(TOP))/emulator/emulator-$(PROJECT)-$*$(JTAG_DEBUG_SUFFIX) +verbose $(EMULATOR_JTAG_VCDPLUS_32) dummybin | tee emulator.log" \
 	--server_cmd="$(RISCV)/bin/openocd $(OPENOCD_DEBUG) \
 	--s $(RISCV)/share/openocd/scripts" \
-	$(abspath $(TOP))/scripts/FreedomSim.py \
+	$(abspath $(TOP))/scripts/RocketSim.py \
 	$(JTAG_DTM_TEST)
 	date > $@
 
@@ -255,7 +255,7 @@ stamps/%/emulator-jtag-dtm-64-$(JTAG_DTM_TEST).stamp:  stamps/%/emulator$(JTAG_S
 	--sim_cmd "$(abspath $(TOP))/emulator/emulator-$(PROJECT)-$*$(JTAG_DEBUG_SUFFIX) +verbose $(EMULATOR_JTAG_VCDPLUS_64) dummybin | tee emulator.log" \
 	--server_cmd="$(RISCV)/bin/openocd $(OPENOCD_DEBUG) \
 	--s $(RISCV)/share/openocd/scripts" \
-	$(abspath $(TOP))/scripts/FreedomSim.py \
+	$(abspath $(TOP))/scripts/RocketSim.py \
 	$(JTAG_DTM_TEST)
 	date > $@
 
diff --git a/scripts/RocketSim.cfg b/scripts/RocketSim.cfg
new file mode 100644
index 00000000..fd6575c2
--- /dev/null
+++ b/scripts/RocketSim.cfg
@@ -0,0 +1,19 @@
+adapter_khz     10000
+
+interface remote_bitbang
+remote_bitbang_host localhost
+#$::env(REMOTE_BITBANG_HOST)
+remote_bitbang_port $::env(JTAG_VPI_PORT)
+
+set _CHIPNAME riscv
+jtag newtap $_CHIPNAME cpu -irlen 5
+
+set _TARGETNAME $_CHIPNAME.cpu
+target create $_TARGETNAME riscv -chain-position $_TARGETNAME -rtos riscv
+
+riscv set_reset_timeout_sec 120
+riscv set_command_timeout_sec 120
+
+init
+halt
+echo "Ready for Remote Connections"
diff --git a/scripts/RocketSim.py b/scripts/RocketSim.py
new file mode 100644
index 00000000..9d836121
--- /dev/null
+++ b/scripts/RocketSim.py
@@ -0,0 +1,16 @@
+import targets
+import testlib
+
+class RocketSimHart(targets.Hart):
+    pass
+
+class RocketSim(targets.Target):
+    harts = [RocketSimHart()]
+    timeout_sec = 6000
+    server_timeout_sec = 60*60
+    openocd_config_path = "RocketSim.cfg"
+
+    def create(self):
+        print "STARTING A SIMULATION"
+        print self.sim_cmd
+        return testlib.VcsSim(sim_cmd=self.sim_cmd, debug=False)
diff --git a/src/main/scala/devices/debug/Periphery.scala b/src/main/scala/devices/debug/Periphery.scala
index 128fc128..17c10e2d 100644
--- a/src/main/scala/devices/debug/Periphery.scala
+++ b/src/main/scala/devices/debug/Periphery.scala
@@ -49,7 +49,8 @@ trait HasPeripheryDebugBundle {
       val dtm = Module(new SimDTM).connect(c, r, d, out)
     }
     debug.systemjtag.foreach { sj =>
-      val jtag = Module(new JTAGVPI(tckHalfPeriod = tckHalfPeriod, cmdDelay = cmdDelay)).connect(sj.jtag, sj.reset, r, out)
+      //val jtag = Module(new JTAGVPI(tckHalfPeriod = tckHalfPeriod, cmdDelay = cmdDelay)).connect(sj.jtag, sj.reset, r, out)
+      val jtag = Module(new SimJTAG(tickDelay=3)).connect(sj.jtag, sj.reset, c, r, out)
       sj.mfr_id := p(JtagDTMKey).idcodeManufId.U(11.W)
     }
     debug.psd.foreach { _ <> psd }
@@ -112,6 +113,36 @@ class SimDTM(implicit p: Parameters) extends BlackBox {
   }
 }
 
+class SimJTAG(tickDelay: Int = 50) extends BlackBox(Map("TICK_DELAY" -> IntParam(tickDelay))) {
+  val io = new Bundle {
+    val clock = Clock(INPUT)
+    val reset = Bool(INPUT)
+    val jtag = new JTAGIO(hasTRSTn = true)
+    val enable = Bool(INPUT)
+    val init_done = Bool(INPUT)
+    val exit = UInt(OUTPUT, 32)
+  }
+
+  def connect(dutio: JTAGIO, jtag_reset: Bool, tbclock: Clock, tbreset: Bool, tbsuccess: Bool) = {
+    dutio <> io.jtag
+    jtag_reset := tbreset
+
+    io.clock := tbclock
+    io.reset := tbreset
+
+    io.enable    := ~tbreset
+    io.init_done := ~tbreset
+
+    // Success is determined by the gdbserver
+    // which is controlling this simulation.
+    tbsuccess := io.exit === UInt(1)
+    when (io.exit >= UInt(2)) {
+      printf("*** FAILED *** (exit code = %d)\n", io.exit >> UInt(1))
+      stop(1)
+    }
+  }
+}
+
 class JTAGVPI(tckHalfPeriod: Int = 2, cmdDelay: Int = 2)(implicit val p: Parameters)
     extends BlackBox ( Map ("TCK_HALF_PERIOD" -> IntParam(tckHalfPeriod),
       "CMD_DELAY" -> IntParam(cmdDelay))) {