Posted on September 30, 2016 at 18:22
Hello
I have 2 PCB with STM32L476. The same code is running on each PCB (both board have been programmed with the STlink-utility and the same binary file). The RTC is configured to provide a 1Hz IRQ. The RTC clock is the 32kHz LSI.On the first PCB, the RTC is working perfectly since months.***On the second PCB, the RTC was working up to tonight, 3AM.***The RTC provides something like a 2Hz IRQ with a lot of jitter :- First IRQ @ T0 + 656ms- Second IRQ @ T1 + 566ms- Third IRQ @ T2 + 746ms- ...code : /* RTC init function */void MX_RTC_Init(void){ RTC_TimeTypeDef sTime; RTC_DateTypeDef sDate; RTC_AlarmTypeDef sAlarm; /**Initialize RTC and set the Time and Date */ hrtc.Instance = RTC; hrtc.Init.HourFormat = RTC_HOURFORMAT_24; hrtc.Init.AsynchPrediv = 127; hrtc.Init.SynchPrediv = 249; hrtc.Init.OutPut = RTC_OUTPUT_DISABLE; hrtc.Init.OutPutRemap = RTC_OUTPUT_REMAP_NONE; hrtc.Init.OutPutPolarity = RTC_OUTPUT_POLARITY_HIGH; hrtc.Init.OutPutType = RTC_OUTPUT_TYPE_OPENDRAIN; HAL_RTC_Init(&hrtc); sTime.Hours = 0; sTime.Minutes = 0; sTime.Seconds = 0; sTime.DayLightSaving = RTC_DAYLIGHTSAVING_NONE; sTime.StoreOperation = RTC_STOREOPERATION_RESET; HAL_RTC_SetTime(&hrtc, &sTime, RTC_FORMAT_BIN); sDate.WeekDay = RTC_WEEKDAY_MONDAY; sDate.Month = RTC_MONTH_JANUARY; sDate.Date = 1; sDate.Year = 0; HAL_RTC_SetDate(&hrtc, &sDate, RTC_FORMAT_BIN); /**Enable the Alarm A */ sAlarm.AlarmTime.Hours = 0; sAlarm.AlarmTime.Minutes = 0; sAlarm.AlarmTime.Seconds = 0; sAlarm.AlarmTime.SubSeconds = 0; sAlarm.AlarmTime.DayLightSaving = RTC_DAYLIGHTSAVING_NONE; sAlarm.AlarmTime.StoreOperation = RTC_STOREOPERATION_RESET; sAlarm.AlarmMask = RTC_ALARMMASK_ALL; sAlarm.AlarmSubSecondMask = RTC_ALARMSUBSECONDMASK_ALL; sAlarm.AlarmDateWeekDaySel = RTC_ALARMDATEWEEKDAYSEL_DATE; sAlarm.AlarmDateWeekDay = 1; sAlarm.Alarm = RTC_ALARM_A; HAL_RTC_SetAlarm_IT(&hrtc, &sAlarm, RTC_FORMAT_BIN);}The timeline provided by IAR shows a double IRQ... At this point I do not understand anything anymore... Thank you for your help
