vrefint-issue.c

/*
stm32l0xx_hal_conf.h
#define HAL_MODULE_ENABLED
#define HAL_DMA_MODULE_ENABLED
#define HAL_FLASH_MODULE_ENABLED
#define HAL_GPIO_MODULE_ENABLED
#define HAL_PWR_MODULE_ENABLED
#define HAL_RCC_MODULE_ENABLED
#define HAL_RTC_MODULE_ENABLED
#define HAL_SPI_MODULE_ENABLED
#define HAL_CORTEX_MODULE_ENABLED
*/

#include "stm32l0xx_hal.h"
#include "stm32l0xx_nucleo.h"

#define RTC_ASYNCH_PREDIV  0x07
#define RTC_SYNCH_PREDIV   0x0FFF

RTC_HandleTypeDef RtcHandle;

static void SystemClock_Config(void);
static void RTC_TimeStampConfig(void);

int main(void)
{ 
  HAL_Init();
  SystemClock_Config();
  HAL_SuspendTick();

  RtcHandle.Instance = RTC; 
  RtcHandle.Init.HourFormat = RTC_HOURFORMAT_12;
  RtcHandle.Init.AsynchPrediv = RTC_ASYNCH_PREDIV;
  RtcHandle.Init.SynchPrediv = RTC_SYNCH_PREDIV;
  RtcHandle.Init.OutPut = RTC_OUTPUT_DISABLE;
  RtcHandle.Init.OutPutPolarity = RTC_OUTPUT_POLARITY_HIGH;
  RtcHandle.Init.OutPutType = RTC_OUTPUT_TYPE_OPENDRAIN;
  
  if(HAL_RTC_Init(&RtcHandle) != HAL_OK) while(1);

  RTC_TimeStampConfig();

  // this disables VREFINT in sleep/stop
  // comment out to see the issue/difference
  HAL_PWREx_EnableUltraLowPower();

  while (1)
  {
    // happens in sleep too
    HAL_PWR_EnterSTOPMode(PWR_LOWPOWERREGULATOR_ON, PWR_SLEEPENTRY_WFI);
  }
}

static void SystemClock_Config(void)
{
  RCC_ClkInitTypeDef RCC_ClkInitStruct;
  RCC_OscInitTypeDef RCC_OscInitStruct;
  
  __PWR_CLK_ENABLE();
  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE2);
  
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_MSI;
  RCC_OscInitStruct.MSIState = RCC_MSI_ON;
  RCC_OscInitStruct.MSIClockRange = RCC_MSIRANGE_5;
  RCC_OscInitStruct.MSICalibrationValue = 0x00;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
  if(HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK) while(1);

  RCC_ClkInitStruct.ClockType = (RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_PCLK1 | RCC_CLOCKTYPE_PCLK2);
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_MSI;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;  
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;  
  if(HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_0) != HAL_OK) while(1);
}

static void RTC_TimeStampConfig(void)
{
  RTC_DateTypeDef sdatestructure;
  RTC_TimeTypeDef stimestructure;
  RTC_TamperTypeDef stamperstructure;
  
  stamperstructure.Filter = RTC_TAMPERFILTER_DISABLE;
  stamperstructure.Tamper = RTC_TAMPER_2;
  stamperstructure.Trigger = RTC_TAMPERTRIGGER_RISINGEDGE;
  stamperstructure.SamplingFrequency = RTC_TAMPERSAMPLINGFREQ_RTCCLK_DIV256;
  stamperstructure.PrechargeDuration = RTC_TAMPERPRECHARGEDURATION_1RTCCLK ;
  stamperstructure.TamperPullUp = RTC_TAMPER_PULLUP_DISABLE;
  stamperstructure.TimeStampOnTamperDetection = RTC_TIMESTAMPONTAMPERDETECTION_ENABLE;
  HAL_RTCEx_SetTamper(&RtcHandle, &stamperstructure);
  
  HAL_RTCEx_SetTimeStamp_IT(&RtcHandle, RTC_TIMESTAMPEDGE_RISING, RTC_TIMESTAMPPIN_PC13);
  
  __HAL_RTC_TIMESTAMP_CLEAR_FLAG(&RtcHandle,RTC_FLAG_TSF);

  sdatestructure.Year = 0x14;
  sdatestructure.Month = RTC_MONTH_APRIL;
  sdatestructure.Date = 0x14;
  sdatestructure.WeekDay = RTC_WEEKDAY_MONDAY;
  if(HAL_RTC_SetDate(&RtcHandle,&sdatestructure,FORMAT_BCD) != HAL_OK) while(1);
  
  stimestructure.Hours = 0x08;
  stimestructure.Minutes = 0x10;
  stimestructure.Seconds = 0x00;
  stimestructure.TimeFormat = RTC_HOURFORMAT12_AM;
  stimestructure.DayLightSaving = RTC_DAYLIGHTSAVING_NONE ;
  stimestructure.StoreOperation = RTC_STOREOPERATION_RESET;
  if(HAL_RTC_SetTime(&RtcHandle,&stimestructure,FORMAT_BCD) != HAL_OK) while(1);
}

void HAL_RTCEx_TimeStampEventCallback(RTC_HandleTypeDef *hrtc)
{
  RTC_DateTypeDef sTimeStampDateget;
  RTC_TimeTypeDef sTimeStampget;

  __HAL_RTC_TAMPER_CLEAR_FLAG(hrtc,RTC_FLAG_TAMP2F);

  HAL_RTCEx_GetTimeStamp(&RtcHandle, &sTimeStampget, &sTimeStampDateget, FORMAT_BIN);
}

void HAL_RTC_MspInit(RTC_HandleTypeDef *hrtc __attribute((unused)))
{
  RCC_OscInitTypeDef RCC_OscInitStruct;
  RCC_PeriphCLKInitTypeDef  PeriphClkInitStruct;

  RCC_OscInitStruct.OscillatorType =  RCC_OSCILLATORTYPE_LSI | RCC_OSCILLATORTYPE_LSE;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
  RCC_OscInitStruct.LSEState = RCC_LSE_ON;
  RCC_OscInitStruct.LSIState = RCC_LSI_OFF;
  if(HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK) while(1);

  PeriphClkInitStruct.PeriphClockSelection = RCC_PERIPHCLK_RTC;
  PeriphClkInitStruct.RTCClockSelection = RCC_RTCCLKSOURCE_LSE;
  if(HAL_RCCEx_PeriphCLKConfig(&PeriphClkInitStruct) != HAL_OK) while(1);

  __HAL_RCC_RTC_ENABLE();
  HAL_NVIC_SetPriority(RTC_IRQn, 0x0, 0);
  HAL_NVIC_EnableIRQ(RTC_IRQn);
}

void RTC_IRQHandler(void)
{
  HAL_RTCEx_TamperTimeStampIRQHandler(&RtcHandle);
}