STM32降频后SPIFLASH读写异常

2万 · 2020-10-11 22:19

STM32L431单片机，如果一开机就跑80MHZ，SpiFlash读写正常。
如果一开机就跑20MHZ，SpiFlash读写也正常。

但是一旦启用智能低功耗模式，从80M切换到20MHZ，，，按照上电的统一代码流程，复位了SPI接口，重新初始化SPI，但是SpiFlash读写偶尔出现异常。

2万 · 2020-10-11 22:23

楼主程序可以公开吗？贴程序看下吧，这么说看不出什么原因

2万 · 2020-10-11 22:28

SpiFlash芯片初始化函数如下：
HAL_StatusTypeDef  bsp_w25qxx_init(void)
{
      GPIO_InitTypeDef  GPIO_InitStruct;

      /*## Enable peripherals and GPIO Clocks #################################*/
      //Enable GPIO clock
      __HAL_RCC_GPIOB_CLK_ENABLE();
      //Enable SPI2 clock
      __HAL_RCC_SPI2_CLK_ENABLE();

      /*## Configure peripheral GPIO ##########################################*/
      //SPI CS GPIO pin configuration
      //PB2-power, PB12-CS,
      GPIO_InitStruct.Pin = GPIO_PIN_2 | GPIO_PIN_12;
      GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
      GPIO_InitStruct.Pull = GPIO_PULLDOWN;
      GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
      HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);
      //PB2-power-on
      HAL_GPIO_WritePin(GPIOB, GPIO_PIN_2, GPIO_PIN_SET);
      HAL_GPIO_WritePin(W25QXX_HWCS_GPIO_PORT, W25QXX_HWCS_PIN, GPIO_PIN_SET);
      //SPI SCK MOSI MISO GPIO pin configuration
      //PB13-SCK, PB14-MISO, PB15-MOSI
      GPIO_InitStruct.Pin    = GPIO_PIN_13 | GPIO_PIN_14 | GPIO_PIN_15;
      GPIO_InitStruct.Mode    = GPIO_MODE_AF_PP;
      GPIO_InitStruct.Pull    = GPIO_PULLDOWN;
      GPIO_InitStruct.Speed    = GPIO_SPEED_FREQ_HIGH;
      GPIO_InitStruct.Alternate = GPIO_AF5_SPI2;
      HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);

      /*## Configure the SPI peripheral #######################################*/
      //Set the SPI parameters
      SpiDataFlashHandle.Instance             = SPI2;
      HAL_SPI_DeInit(&SpiDataFlashHandle);//SPI-DeInit
      __HAL_RCC_SPI2_FORCE_RESET();
      __HAL_RCC_SPI2_RELEASE_RESET();
      if(UserUsageCfg.LowPowerRunFlag){
            SpiDataFlashHandle.Init.BaudRatePrescaler = SPI_BAUDRATEPRESCALER_2;//20M/2=10M, STM32L4 SPI2 MaxCLK <= 40M
      }else{
            SpiDataFlashHandle.Init.BaudRatePrescaler = SPI_BAUDRATEPRESCALER_4;//80M/4=20M, STM32L4 SPI2 MaxCLK <= 40M
      }
      SpiDataFlashHandle.Init.Direction       = SPI_DIRECTION_2LINES;
      SpiDataFlashHandle.Init.CLKPhase       = SPI_PHASE_1EDGE;
      SpiDataFlashHandle.Init.CLKPolarity    = SPI_POLARITY_LOW;
      SpiDataFlashHandle.Init.CRCCalculation = SPI_CRCCALCULATION_DISABLE;
      SpiDataFlashHandle.Init.CRCPolynomial    = 7;
      SpiDataFlashHandle.Init.DataSize       = SPI_DATASIZE_8BIT;
      SpiDataFlashHandle.Init.FirstBit       = SPI_FIRSTBIT_MSB;
      SpiDataFlashHandle.Init.NSS             = SPI_NSS_SOFT;
      SpiDataFlashHandle.Init.TIMode          = SPI_TIMODE_DISABLE;
      SpiDataFlashHandle.Init.Mode             = SPI_MODE_MASTER;
      if(HAL_SPI_Init(&SpiDataFlashHandle) != HAL_OK)       {
            return HAL_ERROR;//Initialization Error
      }else{
            return HAL_OK;
      }
}

2万 · 2020-10-11 22:31

应该是SPI重新配置后，哪里没配置成功吧；

2万 · 2020-10-11 22:36

用示波器先看下相关的引脚

2万 · 2020-10-11 22:42

SPI本身跟频率无关，看看相关初始化函数。

1万 · 2020-10-11 22:45

初始化之后延时一段时间试试

2万 · 2020-10-11 22:50

应该不是降频的问题等待一个周期之后在看看是不是还是异常

2万 · 2020-10-11 22:54

好的，我明天去单位试一下，多谢各位大侠了哈