diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/jtag/bitbang.c | 40 |
1 files changed, 19 insertions, 21 deletions
diff --git a/src/jtag/bitbang.c b/src/jtag/bitbang.c index 24346712..0f462a83 100644 --- a/src/jtag/bitbang.c +++ b/src/jtag/bitbang.c @@ -172,35 +172,33 @@ 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++) { + int val=0; + int tms=(bit_cnt==scan_size-1) ? 1 : 0; + int tdi; + int bytec=bit_cnt/8; + int bcval=1<<(bit_cnt % 8); + /* 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 */ - if ((type != SCAN_IN) && ((buffer[bit_cnt/8] >> (bit_cnt % 8)) & 0x1)) - { - 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, (bit_cnt==scan_size-1) ? 1 : 0, 0); - bitbang_interface->write(1, (bit_cnt==scan_size-1) ? 1 : 0, 0); - } + tdi=0; + if ((type != SCAN_IN) && (buffer[bytec] & bcval)) + tdi=1; + + bitbang_interface->write(0, tms, tdi); + + if (type!=SCAN_OUT) + val=bitbang_interface->read(); + + bitbang_interface->write(1, tms, tdi); 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); + if (val) + buffer[bytec] |= bcval; else - buffer[(bit_cnt)/8] &= ~(1 << ((bit_cnt) % 8)); + buffer[bytec] &= ~bcval; } } |