X-Git-Url: https://review.openocd.org/gitweb?a=blobdiff_plain;f=src%2Fjtag%2Fbitbang.c;h=16b5f1918b3fe6f317d3234b8d2c6fe4cc9a92ab;hb=afe5371bc8bde3fc1a833c3d7e459920711a9584;hp=19afdbf0b8454397547c71949fde276c144b109e;hpb=6ae83f5cf8ddf505498b535cb167550a54271606;p=openocd.git diff --git a/src/jtag/bitbang.c b/src/jtag/bitbang.c index 19afdbf0b8..16b5f1918b 100644 --- a/src/jtag/bitbang.c +++ b/src/jtag/bitbang.c @@ -41,13 +41,16 @@ bitbang_interface_t *bitbang_interface; int bitbang_execute_queue(void); +/* The bitbang driver leaves the TCK 0 when in idle */ + + void bitbang_end_state(enum tap_state state) { if (tap_move_map[state] != -1) end_state = state; else { - ERROR("BUG: %i is not a valid end state", state); + LOG_ERROR("BUG: %i is not a valid end state", state); exit(-1); } } @@ -72,31 +75,35 @@ void bitbang_path_move(pathmove_command_t *cmd) { int num_states = cmd->num_states; int state_count; + int tms = 0; state_count = 0; while (num_states) { if (tap_transitions[cur_state].low == cmd->path[state_count]) { - bitbang_interface->write(0, 0, 0); - bitbang_interface->write(1, 0, 0); + tms = 0; } else if (tap_transitions[cur_state].high == cmd->path[state_count]) { - bitbang_interface->write(0, 1, 0); - bitbang_interface->write(1, 1, 0); - } + tms = 1; + } else { - ERROR("BUG: %s -> %s isn't a valid TAP transition", tap_state_strings[cur_state], tap_state_strings[cmd->path[state_count]]); + LOG_ERROR("BUG: %s -> %s isn't a valid TAP transition", tap_state_strings[cur_state], tap_state_strings[cmd->path[state_count]]); exit(-1); } + bitbang_interface->write(0, tms, 0); + bitbang_interface->write(1, tms, 0); + cur_state = cmd->path[state_count]; state_count++; num_states--; } + bitbang_interface->write(0, tms, 0); + end_state = cur_state; } @@ -145,16 +152,6 @@ void bitbang_scan(int ir_scan, enum scan_type type, u8 *buffer, int scan_size) for (bit_cnt = 0; bit_cnt < scan_size; bit_cnt++) { - /* set TMS high on the last bit unless we want to end in TAP_SD/SI */ - int tms; - if ((ir_scan && (end_state == TAP_SI)) || - (!ir_scan && (end_state == TAP_SD))) - { - tms = 0; - } else { - tms = (bit_cnt==scan_size-1) ? 1 : 0; - } - /* if we're just reading the scan, but don't care about the output * default to outputting 'low', this also makes valgrind traces more readable, * as it removes the dependency on an uninitialised value @@ -170,6 +167,16 @@ void bitbang_scan(int ir_scan, enum scan_type type, u8 *buffer, int scan_size) if (type != SCAN_OUT) { + /* + TDO should be sampled on the rising edge, and will change + on the falling edge. + + Because there is no way to read the signal exactly at the rising edge, + read after the rising edge. + + This is plain IEEE 1149 JTAG - nothing specific to the OpenOCD or its JTAG + API. + */ if (bitbang_interface->read()) buffer[(bit_cnt)/8] |= 1 << ((bit_cnt) % 8); else @@ -177,9 +184,14 @@ void bitbang_scan(int ir_scan, enum scan_type type, u8 *buffer, int scan_size) } } - /* Exit1 -> Pause */ + /* TAP_SD & TAP_SI 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(0, 0, 0); if (ir_scan) cur_state = TAP_PI; @@ -200,7 +212,7 @@ int bitbang_execute_queue(void) if (!bitbang_interface) { - ERROR("BUG: Bitbang interface called, but not yet initialized"); + LOG_ERROR("BUG: Bitbang interface called, but not yet initialized"); exit(-1); } @@ -218,16 +230,16 @@ int bitbang_execute_queue(void) { case JTAG_END_STATE: #ifdef _DEBUG_JTAG_IO_ - DEBUG("end_state: %i", cmd->cmd.end_state->end_state); + LOG_DEBUG("end_state: %i", cmd->cmd.end_state->end_state); #endif if (cmd->cmd.end_state->end_state != -1) bitbang_end_state(cmd->cmd.end_state->end_state); break; case JTAG_RESET: #ifdef _DEBUG_JTAG_IO_ - DEBUG("reset trst: %i srst %i", cmd->cmd.reset->trst, cmd->cmd.reset->srst); + LOG_DEBUG("reset trst: %i srst %i", cmd->cmd.reset->trst, cmd->cmd.reset->srst); #endif - if (cmd->cmd.reset->trst == 1) + if ((cmd->cmd.reset->trst == 1) || (cmd->cmd.reset->srst && (jtag_reset_config & RESET_SRST_PULLS_TRST))) { cur_state = TAP_TLR; } @@ -235,7 +247,7 @@ int bitbang_execute_queue(void) break; case JTAG_RUNTEST: #ifdef _DEBUG_JTAG_IO_ - DEBUG("runtest %i cycles, end in %i", cmd->cmd.runtest->num_cycles, cmd->cmd.runtest->end_state); + LOG_DEBUG("runtest %i cycles, end in %i", cmd->cmd.runtest->num_cycles, cmd->cmd.runtest->end_state); #endif if (cmd->cmd.runtest->end_state != -1) bitbang_end_state(cmd->cmd.runtest->end_state); @@ -243,7 +255,7 @@ int bitbang_execute_queue(void) break; case JTAG_STATEMOVE: #ifdef _DEBUG_JTAG_IO_ - DEBUG("statemove end in %i", cmd->cmd.statemove->end_state); + LOG_DEBUG("statemove end in %i", cmd->cmd.statemove->end_state); #endif if (cmd->cmd.statemove->end_state != -1) bitbang_end_state(cmd->cmd.statemove->end_state); @@ -251,13 +263,13 @@ int bitbang_execute_queue(void) break; case JTAG_PATHMOVE: #ifdef _DEBUG_JTAG_IO_ - DEBUG("pathmove: %i states, end in %i", cmd->cmd.pathmove->num_states, cmd->cmd.pathmove->path[cmd->cmd.pathmove->num_states - 1]); + LOG_DEBUG("pathmove: %i states, end in %i", cmd->cmd.pathmove->num_states, cmd->cmd.pathmove->path[cmd->cmd.pathmove->num_states - 1]); #endif bitbang_path_move(cmd->cmd.pathmove); break; case JTAG_SCAN: #ifdef _DEBUG_JTAG_IO_ - DEBUG("%s scan end in %i", (cmd->cmd.scan->ir_scan) ? "IR" : "DR", cmd->cmd.scan->end_state); + LOG_DEBUG("%s scan end in %i", (cmd->cmd.scan->ir_scan) ? "IR" : "DR", cmd->cmd.scan->end_state); #endif if (cmd->cmd.scan->end_state != -1) bitbang_end_state(cmd->cmd.scan->end_state); @@ -271,12 +283,12 @@ int bitbang_execute_queue(void) break; case JTAG_SLEEP: #ifdef _DEBUG_JTAG_IO_ - DEBUG("sleep %i", cmd->cmd.sleep->us); + LOG_DEBUG("sleep %i", cmd->cmd.sleep->us); #endif jtag_sleep(cmd->cmd.sleep->us); break; default: - ERROR("BUG: unknown JTAG command type encountered"); + LOG_ERROR("BUG: unknown JTAG command type encountered"); exit(-1); } cmd = cmd->next;