diff --git a/urjtag/ChangeLog b/urjtag/ChangeLog
index b522b21e..e564f76e 100644
--- a/urjtag/ChangeLog
+++ b/urjtag/ChangeLog
@@ -1,3 +1,14 @@
+2010-02-02  Jie Zhang  <jie.zhang@analog.com>
+
+  * src/tap/state.c (urj_tap_state_name): New.
+    (urj_tap_state_dump): New.
+    (urj_tap_state_dump_2): New.
+    (urj_tap_state_init): Call urj_tap_state_dump.
+    (urj_tap_state_done): Likewise.
+    (urj_tap_state_reset): Likewise.
+    (urj_tap_state_set_trst): Likewise.
+    (urj_tap_state_clock): Call urj_tap_state_dump_2.
+
 2010-02-02  Jie Zhang  <jie.zhang@analog.com>
 
   * src/tap/usbconn/libftdi.c (usbconn_ftdi_write): Make sure
diff --git a/urjtag/src/tap/state.c b/urjtag/src/tap/state.c
index 59c36847..669d48d0 100644
--- a/urjtag/src/tap/state.c
+++ b/urjtag/src/tap/state.c
@@ -26,6 +26,46 @@
 #include <urjtag/tap_state.h>
 #include <urjtag/chain.h>
 
+static const char *
+urj_tap_state_name (int state)
+{
+    switch (state)
+    {
+    case URJ_TAP_STATE_UNKNOWN_STATE:		return "UNKNOWN_STATE";
+    case URJ_TAP_STATE_TEST_LOGIC_RESET:	return "TEST_LOGIC_RESET";
+    case URJ_TAP_STATE_RUN_TEST_IDLE:		return "RUN_TEST_IDLE";
+    case URJ_TAP_STATE_SELECT_DR_SCAN:		return "SELECT_DR_SCAN";
+    case URJ_TAP_STATE_CAPTURE_DR:		return "CAPTURE_DR";
+    case URJ_TAP_STATE_SHIFT_DR:		return "SHIFT_DR";
+    case URJ_TAP_STATE_EXIT1_DR:		return "EXIT1_DR";
+    case URJ_TAP_STATE_PAUSE_DR:		return "PAUSE_DR";
+    case URJ_TAP_STATE_EXIT2_DR:		return "EXIT2_DR";
+    case URJ_TAP_STATE_UPDATE_DR:		return "UPDATE_DR";
+    case URJ_TAP_STATE_SELECT_IR_SCAN:		return "SELECT_IR_SCAN";
+    case URJ_TAP_STATE_CAPTURE_IR:		return "CAPTURE_IR";
+    case URJ_TAP_STATE_SHIFT_IR:		return "SHIFT_IR";
+    case URJ_TAP_STATE_EXIT1_IR:		return "EXIT1_IR";
+    case URJ_TAP_STATE_PAUSE_IR:		return "PAUSE_IR";
+    case URJ_TAP_STATE_EXIT2_IR:		return "EXIT2_IR";
+    case URJ_TAP_STATE_UPDATE_IR:		return "UPDATE_IR";
+    default:					return "??????";
+    }
+}
+
+static void
+urj_tap_state_dump (int state)
+{
+    urj_log (URJ_LOG_LEVEL_DEBUG, "tap_state: %s\n",
+             urj_tap_state_name (state));
+}
+
+static void
+urj_tap_state_dump_2 (int state0, int state1, int tms)
+{
+    urj_log (URJ_LOG_LEVEL_DEBUG, "tap_state: %16s =(tms:%d)=> %s\n",
+             urj_tap_state_name (state0), tms, urj_tap_state_name (state1));
+}
+
 int
 urj_tap_state (urj_chain_t *chain)
 {
@@ -35,18 +75,21 @@ urj_tap_state (urj_chain_t *chain)
 int
 urj_tap_state_init (urj_chain_t *chain)
 {
+    urj_tap_state_dump (URJ_TAP_STATE_UNKNOWN_STATE);
     return chain->state = URJ_TAP_STATE_UNKNOWN_STATE;
 }
 
 int
 urj_tap_state_done (urj_chain_t *chain)
 {
+    urj_tap_state_dump (URJ_TAP_STATE_UNKNOWN_STATE);
     return chain->state = URJ_TAP_STATE_UNKNOWN_STATE;
 }
 
 int
 urj_tap_state_reset (urj_chain_t *chain)
 {
+    urj_tap_state_dump (URJ_TAP_STATE_TEST_LOGIC_RESET);
     return chain->state = URJ_TAP_STATE_TEST_LOGIC_RESET;
 }
 
@@ -64,12 +107,15 @@ urj_tap_state_set_trst (urj_chain_t *chain, int old_trst, int new_trst)
             chain->state = URJ_TAP_STATE_UNKNOWN_STATE;
     }
 
+    urj_tap_state_dump (chain->state);
     return chain->state;
 }
 
 int
 urj_tap_state_clock (urj_chain_t *chain, int tms)
 {
+    int oldstate = chain->state;
+
     if (tms)
     {
         switch (chain->state)
@@ -154,5 +200,6 @@ urj_tap_state_clock (urj_chain_t *chain, int tms)
         }
     }
 
+    urj_tap_state_dump_2 (oldstate, chain->state, tms);
     return chain->state;
 }