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Georg Acher <acher@in.tum.de> corrected TDO sampling 

git-svn-id: svn://svn.berlios.de/openocd/trunk@1016 b42882b7-edfa-0310-969c-e2dbd0fdcd60
This commit is contained in:
oharboe 2008-10-05 19:44:41 +00:00
parent 4eda44db36
commit 9807a00206
1 changed files with 19 additions and 21 deletions
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40
src/jtag/bitbang.c
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@ -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++) 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 /* 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, * default to outputting 'low', this also makes valgrind traces more readable,
* as it removes the dependency on an uninitialised value * as it removes the dependency on an uninitialised value
*/ */
if ((type != SCAN_IN) && ((buffer[bit_cnt/8] >> (bit_cnt % 8)) & 0x1)) tdi=0;
{ if ((type != SCAN_IN) && (buffer[bytec] & bcval))
bitbang_interface->write(0, (bit_cnt==scan_size-1) ? 1 : 0, 1); tdi=1;
bitbang_interface->write(1, (bit_cnt==scan_size-1) ? 1 : 0, 1);
} else { bitbang_interface->write(0, tms, tdi);
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)
} val=bitbang_interface->read();
bitbang_interface->write(1, tms, tdi);
if (type != SCAN_OUT) if (type != SCAN_OUT)
{ {
/* if (val)
TDO should be sampled on the rising edge, and will change buffer[bytec] |= bcval;
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 else
buffer[(bit_cnt)/8] &= ~(1 << ((bit_cnt) % 8)); buffer[bytec] &= ~bcval;
} }
} }