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Use TCC LUPD lock when updating CCB

This commit is contained in:
Dan Halbert 2019-02-28 19:53:35 -05:00
parent 2c9fbb5d40
commit 808304e827
1 changed files with 18 additions and 18 deletions
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36
ports/atmel-samd/common-hal/pulseio/PWMOut.c
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@ -328,32 +328,29 @@ extern void common_hal_pulseio_pwmout_set_duty_cycle(pulseio_pwmout_obj_t* self,
#endif
#ifdef SAMD51
Tc* tc = tc_insts[t->index];
while (tc->COUNT16.SYNCBUSY.bit.CC1 != 0) {
// Wait for a previous value to be written. This can wait up to one period so we do
// other stuff in the meantime.
#ifdef MICROPY_VM_HOOK_LOOP
MICROPY_VM_HOOK_LOOP
#endif
}
while (tc->COUNT16.SYNCBUSY.bit.CC1 != 0) {}
tc->COUNT16.CCBUF[1].reg = adjusted_duty;
#endif
} else {
uint32_t adjusted_duty = ((uint64_t) tcc_periods[t->index]) * duty / 0xffff;
uint8_t channel = tcc_channel(t);
Tcc* tcc = tcc_insts[t->index];
while ((tcc->SYNCBUSY.vec.CC & (1 << channel)) != 0) {
// Wait for a previous value to be written. This can wait up to one period so we do
// other stuff in the meantime.
#ifdef MICROPY_VM_HOOK_LOOP
MICROPY_VM_HOOK_LOOP
#endif
}
// Write into the CC buffer register, which will be transferred to the
// CC register on an UPDATE (when period is finished).
// Do clock domain syncing as necessary.
while (tcc->SYNCBUSY.reg != 0) {}
// Lock out double-buffering while updating the CCB value.
tcc->CTRLBSET.bit.LUPD = 1;
#ifdef SAMD21
tcc->CCB[channel].reg = adjusted_duty;
#endif
#ifdef SAMD51
tcc->CCBUF[channel].reg = adjusted_duty;
#endif
tcc->CTRLBCLR.bit.LUPD = 1;
}
}
@ -368,7 +365,12 @@ uint16_t common_hal_pulseio_pwmout_get_duty_cycle(pulseio_pwmout_obj_t* self) {
Tcc* tcc = tcc_insts[t->index];
uint8_t channel = tcc_channel(t);
uint32_t cv = 0;
while (tcc->SYNCBUSY.bit.CTRLB) {}
#ifdef SAMD21
// If CCBV (CCB valid) is set, the CCB value hasn't yet been copied
// to the CC value.
if ((tcc->STATUS.vec.CCBV & (1 << channel)) != 0) {
cv = tcc->CCB[channel].reg;
} else {
@ -425,7 +427,7 @@ void common_hal_pulseio_pwmout_set_frequency(pulseio_pwmout_obj_t* self,
tc->COUNT16.CC[0].reg = new_top;
#endif
#ifdef SAMD51
while (tc->COUNT16.SYNCBUSY.reg != 0) {
while (tc->COUNT16.SYNCBUSY.reg != 0) {}
/* Wait for sync */
}
tc->COUNT16.CCBUF[0].reg = new_top;
@ -438,14 +440,12 @@ void common_hal_pulseio_pwmout_set_frequency(pulseio_pwmout_obj_t* self,
tcc->CTRLA.bit.PRESCALER = new_divisor;
tcc_set_enable(tcc, true);
}
while (tcc->SYNCBUSY.reg != 0) {}
tcc_periods[t->index] = new_top;
#ifdef SAMD21
tcc->PERB.bit.PERB = new_top;
#endif
#ifdef SAMD51
while (tcc->SYNCBUSY.reg != 0) {
/* Wait for sync */
}
tcc->PERBUF.bit.PERBUF = new_top;
#endif
}