Posted on May 17, 2011 at 13:18Hello,
i have a Problem configuring the RTC prescaler.
This is my code:
// -----------------------------
// Real Time Clock konfiguration
// -----------------------------
void RTC_Configuration (void)
{
RCC_APB1PeriphClockCmd(RCC_APB1Periph_BKP | RCC_APB1Periph_PWR, ENABLE); // Enable PWR and BKP clocks
PWR_BackupAccessCmd(ENABLE); // Allow access to Backup Registers
BKP_DeInit(); // Reset Backup Domain
RCC_LSEConfig(RCC_LSE_ON);
while (RCC_GetFlagStatus(RCC_FLAG_LSERDY) == RESET); // Wait till LSE is ready
RCC_RTCCLKConfig(RCC_RTCCLKSource_LSE); // Select LSE as RTC Clock Source
RCC_RTCCLKCmd(ENABLE); // Enable RTC Clock
RTC_WaitForSynchro(); // Wait for RTC registers synchronization
RTC_WaitForLastTask(); // Wait until last write operation on RTC registers has finished
RTC_ITConfig(RTC_IT_SEC, ENABLE); // Enable the RTC Second
RTC_WaitForLastTask(); // Wait until last write operation on RTC registers has finishe
// Set RTC prescaler: set RTC period to 1sec
RTC_SetPrescaler(32767); // RTC period = RTCCLK/RTC_PR = (32.768 KHz)/(32767+1)
RTC_WaitForLastTask(); // Wait until last write operation on RTC registers has finished
}
It doesnt matter which value i give the RTC_SetPrescaler function (32767 or 2 oder 16000) the Interrupt period is allways 1.6ms.
I am using an external 32,768kHz Quartz.
What am i doing wrong or is there missing something?
Thanks
