diff options
| -rw-r--r-- | src/jtag/bitbang.c | 34 |
1 files changed, 13 insertions, 21 deletions
diff --git a/src/jtag/bitbang.c b/src/jtag/bitbang.c index fe5f86c4..ea1f016c 100644 --- a/src/jtag/bitbang.c +++ b/src/jtag/bitbang.c @@ -84,12 +84,12 @@ static void bitbang_end_state(tap_state_t state) } } -static void bitbang_state_move(void) +static void bitbang_state_move(int skip) { int i=0, tms=0; u8 tms_scan = tap_get_tms_path(tap_get_state(), tap_get_end_state()); - for (i = 0; i < 7; i++) + for (i = skip; i < 7; i++) { tms = (tms_scan >> i) & 1; bitbang_interface->write(0, tms, 0); @@ -146,7 +146,7 @@ static void bitbang_runtest(int num_cycles) if (tap_get_state() != TAP_IDLE) { bitbang_end_state(TAP_IDLE); - bitbang_state_move(); + bitbang_state_move(0); } /* execute num_cycles */ @@ -160,7 +160,7 @@ static void bitbang_runtest(int num_cycles) /* finish in end_state */ bitbang_end_state(saved_end_state); if (tap_get_state() != tap_get_end_state()) - bitbang_state_move(); + bitbang_state_move(0); } @@ -191,7 +191,7 @@ static void bitbang_scan(int ir_scan, enum scan_type type, u8 *buffer, int scan_ else bitbang_end_state(TAP_DRSHIFT); - bitbang_state_move(); + bitbang_state_move(0); bitbang_end_state(saved_end_state); } @@ -227,22 +227,14 @@ static void bitbang_scan(int ir_scan, enum scan_type type, u8 *buffer, int scan_ } } - /* TAP_DRSHIFT & TAP_IRSHIFT are illegal end states, so we always transition to the pause - * state which is a legal stable state from which statemove will work. - * - * Exit1 -> Pause - */ - bitbang_interface->write(0, 0, 0); - bitbang_interface->write(1, 0, 0); - bitbang_interface->write(CLOCK_IDLE(), 0, 0); - - if (ir_scan) - tap_set_state(TAP_IRPAUSE); - else - tap_set_state(TAP_DRPAUSE); - if (tap_get_state() != tap_get_end_state()) - bitbang_state_move(); + { + /* we *KNOW* the above loop transitioned out of + * the shift state, so we skip the first state + * and move directly to the end state. + */ + bitbang_state_move(1); + } } int bitbang_execute_queue(void) @@ -310,7 +302,7 @@ int bitbang_execute_queue(void) #endif if (cmd->cmd.statemove->end_state != TAP_INVALID) bitbang_end_state(cmd->cmd.statemove->end_state); - bitbang_state_move(); + bitbang_state_move(0); break; case JTAG_PATHMOVE: #ifdef _DEBUG_JTAG_IO_ |