RTC SSR Underflow Interrupt on H533 ? (Low Layer Drivers)

[peplegal]

I'm failing to enable that Interrupt using " LL_RTC_EnableIT_SSRU(RTC) " on STM32H33.

Wakeup timer is set to interrupt every 24h (this is working).

Alarm A is configured, but not enabled.

Alarm B is not used.

RTC is set to BCD mode only.

Monitoring SSR register ( via "READ_REG(RTC->SSR)" ) I can see it's counting down from 0xFF ---> 0x00, periodically.

Some Internet folks told me to enable TAMP Interrupt as well...and intercept TAMP IRQ handler instaead of RTC IRQ handler. It didn't work.

Any help would be greatly appreciated.

Thanks.

[Chris21]

I noticed this comment in the HAL header file:

/**
* @brief Enable SSR Underflow interrupt
* @note Bit is write-protected. @ref LL_RTC_DisableWriteProtection function should be called before.
* @rmtoll RTC_CR SSRUIE LL_RTC_EnableIT_SSRU
* @PAram RTCx RTC Instance
* @retval None
*/

[Gyessine]

Hello @peplegal 
the bit is write-protected.
Can you try and call LL_RTC_DisableWriteProtection before calling LL_RTC_EnableIT_SSRU adn see if it solves your problem.
BR
Gyessine

[Gyessine]

Hello @peplegal 
Any updates, did you solve your problem?
BR
Gyessine