diff options
author | oharboe <oharboe@b42882b7-edfa-0310-969c-e2dbd0fdcd60> | 2008-03-26 13:29:48 +0000 |
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committer | oharboe <oharboe@b42882b7-edfa-0310-969c-e2dbd0fdcd60> | 2008-03-26 13:29:48 +0000 |
commit | 4411c2643e41d023a1909b1040361912422be6c0 (patch) | |
tree | 0d3b91dafae9dfdca2bf16473232b8073e5fbdeb /src/jtag/bitbang.c | |
parent | 2df3ca97a70aa600a1dd0f8be59d0ad2d359c16e (diff) |
TAP_SD/SI are now forbidden end states.
jtag_add_reset() now returns void streamlining the API
git-svn-id: svn://svn.berlios.de/openocd/trunk@525 b42882b7-edfa-0310-969c-e2dbd0fdcd60
Diffstat (limited to 'src/jtag/bitbang.c')
-rw-r--r-- | src/jtag/bitbang.c | 86 |
1 files changed, 32 insertions, 54 deletions
diff --git a/src/jtag/bitbang.c b/src/jtag/bitbang.c index 054faf50..a4e415c2 100644 --- a/src/jtag/bitbang.c +++ b/src/jtag/bitbang.c @@ -75,7 +75,7 @@ void bitbang_path_move(pathmove_command_t *cmd) { int num_states = cmd->num_states; int state_count; - int tms; + int tms = 0; state_count = 0; while (num_states) @@ -138,7 +138,6 @@ void bitbang_scan(int ir_scan, enum scan_type type, u8 *buffer, int scan_size) { enum tap_state saved_end_state = end_state; int bit_cnt; - int last_bit, last_bit_in; if (!((!ir_scan && (cur_state == TAP_SD)) || (ir_scan && (cur_state == TAP_SI)))) { @@ -151,7 +150,7 @@ void bitbang_scan(int ir_scan, enum scan_type type, u8 *buffer, int scan_size) bitbang_end_state(saved_end_state); } - for (bit_cnt = 0; bit_cnt < scan_size - 1; bit_cnt++) + for (bit_cnt = 0; bit_cnt < scan_size; bit_cnt++) { /* 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, @@ -159,69 +158,48 @@ void bitbang_scan(int ir_scan, enum scan_type type, u8 *buffer, int scan_size) */ if ((type != SCAN_IN) && ((buffer[bit_cnt/8] >> (bit_cnt % 8)) & 0x1)) { - bitbang_interface->write(0, 0, 1); - bitbang_interface->write(1, 0, 1); + bitbang_interface->write(0, (bit_cnt==scan_size-1) ? 1 : 0, 1); + bitbang_interface->write(1, (bit_cnt==scan_size-1) ? 1 : 0, 1); } else { - bitbang_interface->write(0, 0, 0); - bitbang_interface->write(1, 0, 0); + bitbang_interface->write(0, (bit_cnt==scan_size-1) ? 1 : 0, 0); + bitbang_interface->write(1, (bit_cnt==scan_size-1) ? 1 : 0, 0); } 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 buffer[(bit_cnt)/8] &= ~(1 << ((bit_cnt) % 8)); } } - - if ((type != SCAN_IN) && ((buffer[bit_cnt/8] >> (bit_cnt % 8)) & 0x1)) - last_bit = 1; - else - last_bit = 0; - - if ((ir_scan && (end_state == TAP_SI)) || - (!ir_scan && (end_state == TAP_SD))) - { - bitbang_interface->write(0, 0, last_bit); - bitbang_interface->write(1, 0, last_bit); - - if (type != SCAN_OUT) - last_bit_in = bitbang_interface->read(); - - bitbang_interface->write(0, 0, last_bit); - } + + /* 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; else - { - /* Shift-[ID]R -> Exit1-[ID]R */ - bitbang_interface->write(0, 1, last_bit); - bitbang_interface->write(1, 1, last_bit); - - if (type != SCAN_OUT) - last_bit_in = bitbang_interface->read(); - - /* Exit1-[ID]R -> Pause-[ID]R */ - bitbang_interface->write(0, 0, 0); - bitbang_interface->write(1, 0, 0); - - if (cur_state == TAP_SI) - cur_state = TAP_PI; - else - cur_state = TAP_PD; - - if (cur_state != end_state) - bitbang_state_move(); - else - bitbang_interface->write(0, 0, 0); - } - - if (type != SCAN_OUT) - { - if (last_bit_in) - buffer[(bit_cnt)/8] |= 1 << ((bit_cnt) % 8); - else - buffer[(bit_cnt)/8] &= ~(1 << ((bit_cnt) % 8)); - } + cur_state = TAP_PD; + + if (cur_state != end_state) + bitbang_state_move(); } int bitbang_execute_queue(void) |