Hi,
I am new to STM32 controller and I am using STM32L412RBT6. I was doing baremetal programming for RTC wakeup interrupt. But interrupt is not calling. Below mentioning my code.
/* Enable Clock for Power interface.*/
RCC->APB1ENR1 |= (1U<<28);
/*Disable backup domain write protection*/
PWR->CR1 |= (1U<<8);
/*Enable LSE Clock source and wait until LSERDY bit to set*/
RCC->BDCR |= (1U<<0);
while ((RCC->BDCR & (1U<<1)) == 0);
/*Select LSE as RTC Clock*/
RCC->BDCR |= (1U<<8);
RCC->BDCR &= ~(1U<<9);
/*Enable RTC Clock*/
RCC->BDCR |= (1U<<15);
/* Disable the write protection for RTC registers */
RTC->WPR = 0xCA;
RTC->WPR = 0x53;
/* Check if the Initialization mode is set */
if((RTC->ICSR & (1U<<6))==0)
{
/* Set the Initialization mode */
RTC->ICSR |= (1U<<7);
/* Wait till RTC is in INIT state*/
while((RTC->ICSR & (1U<<6))==0);
}
/* Clear RTC_CR FMT, OSEL, POL and TAMPOE Bits */
RTC->CR &= ~(1U<<6); //FMT
RTC->CR &= ~(1U<<20); //POL
RTC->CR &= ~(1U<<21); //OSEL
RTC->CR &= ~(1U<<22); //OSEL
RTC->CR &= ~(1U<<26); //TAMPOE
/* Set RTC_CR register */
RTC->CR &= ~(1U<<6); //FMT bit set as Zero,Hour Format Selected as 24
RTC->CR &= ~(1U<<20); //POL bit set as Zero, Output polarity selected as high.
RTC->CR &= ~(1U<<21); //OSEL[22:21] set as zero, output selection disabled.
RTC->CR &= ~(1U<<22);
/* Configure the RTC PRER */
RTC->PRER |= 0xFF; // Synchronus value set as 255
RTC->PRER |= (0x7F<<16); // Asynchronus value set as 127.
/* Exit Initialization mode */
RTC->ICSR &= ~(1U<<7); // Clear INIT bit.
/*Set Output type as open drain pullup*/
RTC->CR |= (1U<<30);
/*Disable the Wakeup Timer*/
RTC->CR &= ~(1U<<10);
/*In case of interrupt mode is used, the interrupt source must disabled*/
RTC->CR &= ~(1U<<14);
/* Wait till RTC WUTWF flag is set and if Time out is reached exit */
while ((RTC->ICSR & (1U<<2)) == 0);
/* Clear WUTE in RTC_CR to disable the wakeup timer */
RTC->CR &= ~(1U<<10);
/* Clear flag Wake-Up */
RTC->SCR |= (1U<<2);
/* Poll WUTWF until it is set in RTC_ICSR to make sure the access to wakeup autoreload
counter and to WUCKSEL[2:0] bits is allowed. */
while((RTC->ICSR & (1U<<2))==0);
/* Configure the Wakeup Timer counter and auto clear value */
RTC->WUTR |= (RTC_WAKEUP_TIME_IN_SECONDS-1);
RTC->WUTR |= (WakeUpAutoClr<<16);
/* Configure the clock source */
RTC->CR &= ~(1U<<0);
RTC->CR &= ~(1U<<1);
RTC->CR |= (1U<<2);
/* RTC WakeUpTimer EXTI Configuration: Interrupt configuration */
EXTI->IMR1 |= (1U<<20);
EXTI->RTSR1 |= (1U<<20);
/* Configure the Interrupt in the RTC_CR register */
RTC->CR |= (1U<<14);
/* Enable the Wakeup Timer */
RTC->CR |= (1U<<10);
/* Enable the write protection for RTC registers */
RTC->WPR = 0xFF;
NVIC_EnableIRQ(RTC_WKUP_IRQn);
void RTC_WKUP_IRQHandler(void)
{
EXTI->PR1 |= (1U<<20);
if((RTC->MISR & (1U<<2))!=0)
{
RTC->SCR |= (1U<<2);
count++ ;
}
}
