X-Git-Url: https://review.openocd.org/gitweb?p=openocd.git;a=blobdiff_plain;f=src%2Fjtag%2Fbitbang.c;h=e8d082a7aa0b3f4d2fdca2420e4e37336a29d777;hp=198a741fd78ce66b98f0d2965f62d976483227ca;hb=526fe3d83e118d87af34353a7140c02f3f1a3c19;hpb=ffb51c23fdd753ada2554b8b6283533089153b46 diff --git a/src/jtag/bitbang.c b/src/jtag/bitbang.c index 198a741fd7..e8d082a7aa 100644 --- a/src/jtag/bitbang.c +++ b/src/jtag/bitbang.c @@ -2,6 +2,9 @@ * Copyright (C) 2005 by Dominic Rath * * Dominic.Rath@gmx.de * * * + * Copyright (C) 2007,2008 Øyvind Harboe * + * oyvind.harboe@zylin.com * + * * * This program is free software; you can redistribute it and/or modify * * it under the terms of the GNU General Public License as published by * * the Free Software Foundation; either version 2 of the License, or * @@ -34,20 +37,40 @@ #include #include -#include -#include - bitbang_interface_t *bitbang_interface; + +/* DANGER!!!! clock absolutely *MUST* be 0 in idle or reset won't work! + * + * Set this to 1 and str912 reset halt will fail. + * + * If someone can submit a patch with an explanation it will be greatly + * appreciated, but as far as I can tell (ØH) DCLK is generated upon + * clk=0 in TAP_RTI. Good luck deducing that from the ARM documentation! + * The ARM documentation uses the term "DCLK is asserted while in the TAP_RTI + * state". With hardware there is no such thing as *while* in a state. There + * are only edges. So clk => 0 is in fact a very subtle state transition that + * happens *while* in the TAP_RTI state. "#&¤"#¤&"#&"#& + * + * For "reset halt" the last thing that happens before srst is asserted + * is that the breakpoint is set up. If DCLK is not wiggled one last + * time before the reset, then the breakpoint is not set up and + * "reset halt" will fail to halt. + * + */ +#define CLOCK_IDLE() 0 + 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); } } @@ -63,7 +86,7 @@ void bitbang_state_move(void) { bitbang_interface->write(0, tms, 0); bitbang_interface->write(1, tms, 0); } - bitbang_interface->write(0, tms, 0); + bitbang_interface->write(CLOCK_IDLE(), tms, 0); cur_state = end_state; } @@ -72,31 +95,35 @@ 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(CLOCK_IDLE(), tms, 0); + end_state = cur_state; } @@ -114,12 +141,12 @@ void bitbang_runtest(int num_cycles) } /* execute num_cycles */ - bitbang_interface->write(0, 0, 0); for (i = 0; i < num_cycles; i++) { - bitbang_interface->write(1, 0, 0); bitbang_interface->write(0, 0, 0); + bitbang_interface->write(1, 0, 0); } + bitbang_interface->write(CLOCK_IDLE(), 0, 0); /* finish in end_state */ bitbang_end_state(saved_end_state); @@ -145,16 +172,6 @@ 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 +187,16 @@ 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 +204,14 @@ 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(CLOCK_IDLE(), 0, 0); if (ir_scan) cur_state = TAP_PI; @@ -200,7 +232,7 @@ 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); } @@ -209,22 +241,25 @@ int bitbang_execute_queue(void) */ retval = ERROR_OK; + if(bitbang_interface->blink) + bitbang_interface->blink(1); + while (cmd) { switch (cmd->type) { 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; } @@ -232,7 +267,7 @@ 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); @@ -240,7 +275,7 @@ 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); @@ -248,13 +283,13 @@ 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); @@ -268,16 +303,18 @@ 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; } + if(bitbang_interface->blink) + bitbang_interface->blink(0); return retval; }