STM32F107 excess power consumption in STOP mode

Question

Firstly, I want to say that there is no error on PCB because if I put MCU into standby, consumption is normal - around 5 uA.

I have experience with stop mode on STM32L0, but STM32F1 got to my hand for the first time. For some reason, I can't achieve designed power consumption - it is always near 1 mA, which is 100 times more than it should be.

Furthermore, it looks that MCU just hangs after it's going to stop mode because I stop receiving interrupts from RTC, which have worked before I added instruction for going to stop.

My MCU is STM32F107VB

#include <stm32f1xx_hal.h>

RTC_HandleTypeDef hrtc;

#ifdef __cplusplus
extern "C"
#endif
void SysTick_Handler(void)
{
    HAL_IncTick();
    HAL_SYSTICK_IRQHandler();
}

#ifdef __cplusplus
extern "C"
#endif
void RTC_IRQHandler(void)
{
    HAL_GPIO_TogglePin(GPIOD, GPIO_PIN_7);
    HAL_RTCEx_RTCIRQHandler(&hrtc);
}

void Error_Handler()
{
    __asm("bkpt 255");
    __asm("bx lr");
}

void display_initGpio(void)
{ 
    __HAL_RCC_GPIOB_CLK_ENABLE();
    __HAL_RCC_GPIOC_CLK_ENABLE();
    __HAL_RCC_GPIOD_CLK_ENABLE();
    __HAL_RCC_GPIOE_CLK_ENABLE();

    GPIO_InitTypeDef GPIO_InitStructure;

    GPIO_InitStructure.Pin = GPIO_PIN_3 | GPIO_PIN_5 | GPIO_PIN_8 | GPIO_PIN_9 | GPIO_PIN_14 | GPIO_PIN_15;
    GPIO_InitStructure.Mode = GPIO_MODE_OUTPUT_PP;
    GPIO_InitStructure.Speed = GPIO_SPEED_FREQ_LOW;
    GPIO_InitStructure.Pull = GPIO_NOPULL;
    HAL_GPIO_Init(GPIOB, &GPIO_InitStructure);

    GPIO_InitStructure.Pin = GPIO_PIN_0 | GPIO_PIN_5;
    GPIO_InitStructure.Mode = GPIO_MODE_INPUT;
    GPIO_InitStructure.Speed = GPIO_SPEED_FREQ_LOW;
    GPIO_InitStructure.Pull = GPIO_PULLUP;
    HAL_GPIO_Init(GPIOC, &GPIO_InitStructure);
    
    GPIO_InitStructure.Pin = GPIO_PIN_0 | GPIO_PIN_7 | GPIO_PIN_14;
    GPIO_InitStructure.Mode = GPIO_MODE_OUTPUT_PP;
    GPIO_InitStructure.Speed = GPIO_SPEED_FREQ_LOW;
    GPIO_InitStructure.Pull = GPIO_NOPULL;
    HAL_GPIO_Init(GPIOD, &GPIO_InitStructure);
    
    GPIO_InitStructure.Pin = GPIO_PIN_3 | GPIO_PIN_4 | GPIO_PIN_5 | GPIO_PIN_6;
    GPIO_InitStructure.Mode = GPIO_MODE_INPUT;
    GPIO_InitStructure.Speed = GPIO_SPEED_FREQ_LOW;
    GPIO_InitStructure.Pull = GPIO_NOPULL;
    HAL_GPIO_Init(GPIOD, &GPIO_InitStructure);
    
    GPIO_InitStructure.Pin = GPIO_PIN_9 | GPIO_PIN_10;
    GPIO_InitStructure.Mode = GPIO_MODE_INPUT;
    GPIO_InitStructure.Speed = GPIO_SPEED_FREQ_LOW;
    GPIO_InitStructure.Pull = GPIO_NOPULL;
    HAL_GPIO_Init(GPIOE, &GPIO_InitStructure);
    
    HAL_GPIO_WritePin(GPIOB, GPIO_PIN_3, GPIO_PIN_RESET);       // SCK
    HAL_GPIO_WritePin(GPIOB, GPIO_PIN_5, GPIO_PIN_RESET);       // MOSI
    HAL_GPIO_WritePin(GPIOB, GPIO_PIN_8, GPIO_PIN_RESET);       // A0
    HAL_GPIO_WritePin(GPIOB, GPIO_PIN_9, GPIO_PIN_RESET);       // LCD_RESET
    HAL_GPIO_WritePin(GPIOB, GPIO_PIN_14, GPIO_PIN_RESET);      // LCD_PWR
    HAL_GPIO_WritePin(GPIOB, GPIO_PIN_15, GPIO_PIN_RESET);      // LCD_RESET
    
    HAL_GPIO_WritePin(GPIOD, GPIO_PIN_0, GPIO_PIN_RESET);       // CS
    HAL_GPIO_WritePin(GPIOD, GPIO_PIN_7, GPIO_PIN_RESET);       // LCD_LIGHT
    HAL_GPIO_WritePin(GPIOD, GPIO_PIN_14, GPIO_PIN_RESET);      // LCD_RWR
}

void rtcInit(void)
{
    HAL_PWR_EnableBkUpAccess();
    /* Enable BKP CLK enable for backup registers */
    __HAL_RCC_BKP_CLK_ENABLE();
    /* Peripheral clock enable */
    __HAL_RCC_RTC_ENABLE();
    /* RTC interrupt Init */
    
    hrtc.Instance = RTC;
    hrtc.Init.AsynchPrediv = RTC_AUTO_1_SECOND;
    hrtc.Init.OutPut = RTC_OUTPUTSOURCE_NONE;
    if (HAL_RTC_Init(&hrtc) != HAL_OK)
    {
        Error_Handler();
    }
    
    HAL_RTCEx_SetSecond_IT(&hrtc);
    HAL_NVIC_SetPriority(RTC_IRQn, 0, 0);
    HAL_NVIC_EnableIRQ(RTC_IRQn);
}

void  SystemClock_Config(void)
{
    RCC_OscInitTypeDef RCC_OscInitStruct = { 0 };
    RCC_ClkInitTypeDef RCC_ClkInitStruct = { 0 };
    RCC_PeriphCLKInitTypeDef PeriphClkInit = { 0 };

    __HAL_RCC_AFIO_CLK_ENABLE();
    __HAL_RCC_PWR_CLK_ENABLE();
    
    /** Initializes the RCC Oscillators according to the specified parameters
    * in the RCC_OscInitTypeDef structure.
    */
    RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI | RCC_OSCILLATORTYPE_LSI;
    RCC_OscInitStruct.HSIState = RCC_HSI_ON;
    RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
    RCC_OscInitStruct.LSIState = RCC_LSI_ON;
    RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
    RCC_OscInitStruct.PLL2.PLL2State = RCC_PLL_NONE;
    if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
    {
        Error_Handler();
    }
    /** Initializes the CPU, AHB and APB buses clocks
    */
    RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_SYSCLK
                                | RCC_CLOCKTYPE_PCLK1 | RCC_CLOCKTYPE_PCLK2;
    RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_HSI;
    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)
    {
        Error_Handler();
    }
    PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_RTC;
    PeriphClkInit.RTCClockSelection = RCC_RTCCLKSOURCE_LSI;
    if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit) != HAL_OK)
    {
        Error_Handler();
    }
    /** Configure the Systick interrupt time
    */
    __HAL_RCC_PLLI2S_ENABLE();
    
    HAL_NVIC_SetPriority(RCC_IRQn, 0, 0);
    HAL_NVIC_EnableIRQ(RCC_IRQn);
}

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

    __HAL_AFIO_REMAP_SWJ_NOJTAG();
    HAL_PWR_EnableWakeUpPin(PWR_WAKEUP_PIN1);

    display_initGpio();
    rtcInit();
    
    HAL_Delay(100);
    
    while (1)
    {
        HAL_SuspendTick();
        __HAL_RCC_PWR_CLK_ENABLE();
        HAL_PWR_EnterSTOPMode(PWR_LOWPOWERREGULATOR_ON, PWR_STOPENTRY_WFI); 
    }
}

Answer 1

What is connected to port D pin 3 4 5 6 and port E 9 and 10 ? I assume here that they are not connected to anything and left floating. BTW, even if the problem is supposedly a software issue, it's still a good idea to provide the schematics.

The listed pins are set as inputs without any pull-up or pull-down. If left floating, the input buffer of these pins may receive a voltage that neither a strong "0" nor a "1", but something undefined floating in between. Input buffers are now happy with that and may consume much more power than expected in theses conditions.