Posted on July 18, 2012 at 22:11Hi I am trying to write date and time to the RTC which I later will read.
But something in my RTC configuration doesn’t work and reading the values in debug mode shows that the RTC registers that I try to set never get the new values.
Here is my code:
void Set_RTC()
{
/* Enable the PWR clock */
RCC_APB1ENR.PWREN = 1;
/* Allow access to RTC */
PWR_CR.DBP = 1;
/* LSE used as RTC source clock */
RCC_BDCR.LSEON = 1; //External low-speed oscillator enable
/* Wait till LSE is ready */
while(RCC_BDCR.LSERDY != 1)
{
}
/* Select the RTC Clock Source to LSE */
RCC_BDCR.F8 = 1;
RCC_BDCR.F9 = 0;
/* Wait for RTC APB registers synchronisation */
while(RTC_ISR.RSF != 1)
{
}
RCC_BDCR.RTCEN = 1; //Enable RTC clock <<<
RTC_WPR = 0xCA; //unlock write protection
RTC_WPR = 0x53; //unlock write protection
/* Configure the RTC prescaler */
RTC_PRER = 0x7f00ff; // set SynchPrediv to FF and AsynchPrediv to 7F
//RCC_BDCR.RTCEN = 1; //Enable RTC clock <<<
RTC_ISR.INIT = 1; //enter initialization mode <<<<<< THIS REGISTER NEVER GETS THE NEW VALUE
while(RTC_ISR.INITF != 1) //poll INITF
{
}
/* Configure the RTC PRER */
RTC_PRER = 0x7F;
RTC_PRER |= 0xFF << 16;
RTC_TR = 0x123500; //setting time to 12.35.00
RTC_DR = 0x126718; // set date to 2012-07-18
RTC_CR.F6 = 0; // set FMT 24H format
RTC_ISR.INIT = 0; //exit initialization mode
/* Enable the write protection for RTC registers */
RTC_WPR = 0xFF;
}
I am using a STM32F407 @ 140Mz internal HSI oscillator.
What am I doing wrong?
