Hello All,
The above function is used to config various clocks. For the RTC it contains this
/* Enable Power Clock*/
__HAL_RCC_PWR_CLK_ENABLE();
/* Enable write access to Backup domain */
PWR->CR |= PWR_CR_DBP;
// Wait for above to stabilise
tickstart = HAL_GetTick();
while((PWR->CR & PWR_CR_DBP) == RESET)
{
if((HAL_GetTick() - tickstart ) > RCC_DBP_TIMEOUT_VALUE)
{
return HAL_TIMEOUT;
}
}
They have a 1-2ms timeout on the write access enable bit. But there is no timeout in other HAL code for the same code e.g.
HAL_StatusTypeDef HAL_RTC_SetTime(RTC_HandleTypeDef *hrtc, RTC_TimeTypeDef *sTime, uint32_t Format)
{
uint32_t tmpreg = 0U;
/* Check the parameters */
assert_param(IS_RTC_FORMAT(Format));
assert_param(IS_RTC_DAYLIGHT_SAVING(sTime->DayLightSaving));
assert_param(IS_RTC_STORE_OPERATION(sTime->StoreOperation));
/* Process Locked */
__HAL_LOCK(hrtc);
hrtc->State = HAL_RTC_STATE_BUSY;
if(Format == RTC_FORMAT_BIN)
{
if((hrtc->Instance->CR & RTC_CR_FMT) != (uint32_t)RESET)
{
assert_param(IS_RTC_HOUR12(sTime->Hours));
assert_param(IS_RTC_HOURFORMAT12(sTime->TimeFormat));
}
else
{
sTime->TimeFormat = 0x00U;
assert_param(IS_RTC_HOUR24(sTime->Hours));
}
assert_param(IS_RTC_MINUTES(sTime->Minutes));
assert_param(IS_RTC_SECONDS(sTime->Seconds));
tmpreg = (uint32_t)(((uint32_t)RTC_ByteToBcd2(sTime->Hours) << 16U) | \
((uint32_t)RTC_ByteToBcd2(sTime->Minutes) << 8U) | \
((uint32_t)RTC_ByteToBcd2(sTime->Seconds)) | \
(((uint32_t)sTime->TimeFormat) << 16U));
}
else
{
if((hrtc->Instance->CR & RTC_CR_FMT) != (uint32_t)RESET)
{
tmpreg = RTC_Bcd2ToByte(sTime->Hours);
assert_param(IS_RTC_HOUR12(tmpreg));
assert_param(IS_RTC_HOURFORMAT12(sTime->TimeFormat));
}
else
{
sTime->TimeFormat = 0x00U;
assert_param(IS_RTC_HOUR24(RTC_Bcd2ToByte(sTime->Hours)));
}
assert_param(IS_RTC_MINUTES(RTC_Bcd2ToByte(sTime->Minutes)));
assert_param(IS_RTC_SECONDS(RTC_Bcd2ToByte(sTime->Seconds)));
tmpreg = (((uint32_t)(sTime->Hours) << 16U) | \
((uint32_t)(sTime->Minutes) << 8U) | \
((uint32_t)sTime->Seconds) | \
((uint32_t)(sTime->TimeFormat) << 16U));
}
/* Disable the write protection for RTC registers */
__HAL_RTC_WRITEPROTECTION_DISABLE(hrtc);
/* Set Initialization mode */
if(RTC_EnterInitMode(hrtc) != HAL_OK)
{
/* Enable the write protection for RTC registers */
__HAL_RTC_WRITEPROTECTION_ENABLE(hrtc);
/* Set RTC state */
hrtc->State = HAL_RTC_STATE_ERROR;
/* Process Unlocked */
__HAL_UNLOCK(hrtc);
return HAL_ERROR;
}
else
{
/* Set the RTC_TR register */
hrtc->Instance->TR = (uint32_t)(tmpreg & RTC_TR_RESERVED_MASK);
/* Clear the bits to be configured */
hrtc->Instance->CR &= (uint32_t)~RTC_CR_BCK;
/* Configure the RTC_CR register */
hrtc->Instance->CR |= (uint32_t)(sTime->DayLightSaving | sTime->StoreOperation);
/* Exit Initialization mode */
hrtc->Instance->ISR &= (uint32_t)~RTC_ISR_INIT;
/* If CR_BYPSHAD bit = 0, wait for synchro else this check is not needed */
if((hrtc->Instance->CR & RTC_CR_BYPSHAD) == RESET)
{
if(HAL_RTC_WaitForSynchro(hrtc) != HAL_OK)
{
/* Enable the write protection for RTC registers */
__HAL_RTC_WRITEPROTECTION_ENABLE(hrtc);
hrtc->State = HAL_RTC_STATE_ERROR;
/* Process Unlocked */
__HAL_UNLOCK(hrtc);
return HAL_ERROR;
}
}
/* Enable the write protection for RTC registers */
__HAL_RTC_WRITEPROTECTION_ENABLE(hrtc);
hrtc->State = HAL_RTC_STATE_READY;
__HAL_UNLOCK(hrtc);
return HAL_OK;
}
}
Old hands will know that e.g.
__HAL_LOCK(hrtc);
hrtc->State = HAL_RTC_STATE_BUSY;
is completely junk code, but I just pasted the whole function here 🙂
