/*!
* \brief State transition with TMS set to low.
*/
static void TmsLowTransition(void)
{
CLR_TMS();
CLR_TCK();
SET_TCK();
}
/*!
* \brief Repeat shifting out a TDI value until an expected TDO value appears.
*
* \param len Number of bits to shift.
* \param tdi_val TDI value to shift out.
* \param tdo_exp Expected TDO value. Set to NULL if not available.
* \param tdo_msk Used to mask out don't care TDO values.
* \param sState TAP state during shift operation, either SHIFT-DR or SHIFT-IR. No
* retries are allowed with SHIFT-IR.
* \param eState TAP state after shift operation.
* \param delay Idle time (in microseconds) after each shift.
* \param retries Maximum number of retries. Ignored if expected TDO value is not available.
*
* \return Zero on success, otherwise an error code is returned.
*/
static int ReShift(int len, unsigned char *tdi_val, unsigned char *tdo_exp, unsigned char *tdo_msk,
unsigned char sState, unsigned char eState, long delay, unsigned char retries)
{
int rc = 0;
unsigned char tdo_val[MAX_BITVEC_BYTES];
if (len == 0) {
if (delay) {
TapStateChange(RUN_TEST_IDLE);
XsvfDelay(delay);
}
} else {
int last_byte = (int)((len + 7UL) / 8UL - 1UL);
/*
* Retry loop.
*/
do {
unsigned char *tdi = &tdi_val[last_byte];
unsigned char *tdo = &tdo_val[last_byte];
int bitcnt;
unsigned char bitmsk;
TapStateChange(sState);
/*
* Byte loop.
*/
for(bitcnt = len; bitcnt;) {
*tdo = 0;
/*
* Bit loop. LSB is shifted first.
*/
for (bitmsk = 1; bitmsk && bitcnt; bitmsk <<= 1) {
if (sState != eState && bitcnt == 1) {
/* Exit Shift state with last bit. */
SET_TMS();
TapStateInc();
}
/* Shift TDI in and TDO out. */
if(*tdi & bitmsk) {
SET_TDI();
}
else {
CLR_TDI();
}
CLR_TCK();
/*
* This is time critical, because TDO may be delayed.
* The following decrement of our int value consumes
* some CPU cycles.
*/
bitcnt--;
if(GET_TDO()) {
*tdo |= bitmsk;
}
SET_TCK();
}
tdi--;
tdo--;
}
/*
* Compare captured with expected TDO result.
*/
if (tdo_exp) {
if(BitStringCmp(len, tdo_exp, tdo_val, tdo_msk)) {
rc = XE_TDOMISMATCH;
}
else {
rc = 0;
}
}
/*
* Update TAP controller state.
*/
if (sState != eState) {
if (rc && delay && retries) {
/* The TDO value does not match the expected value. */
TapStateChange(PAUSE_DR);
TapStateChange(SHIFT_DR);
} else {
TapStateChange(eState);
}
/*
* If the XRUNTEST time is non-zero, go to the Run-Test/Idle state
* and wait for the specified number of microseconds.
*/
if (delay) {
PORTA ^= 0x10;
TapStateChange(RUN_TEST_IDLE);
//XsvfDelay(delay);
XsvfClockCycles(delay);
/* In case of another retry, increase idle time by 25%. */
//delay += (delay >> 2);
}
}
} while (rc && retries--);
}
return rc;
}
/*!
* \brief State transition with TMS set to high.
*/
static void TmsHighTransition(void)
{
SET_TMS();
CLR_TCK();
SET_TCK();
}
