STM32-SPI读写外部FLASH（W25Q64）

一、工具

　　1、STM32F103VET6单片机；

　　2、编译环境：TrueSTUDIO

　　3、辅助工具：STM32CubeMX

二、电路原理图

三、单片机系统时钟配置

　　1、时钟源选择：

 　　2、时钟树：

 四、SPI配置

　　1、选用的是SPI1，全双工主机模式（单片机是主机，外部FLASH做从机），片选引脚由软件控制。

　　2、再检查一下SPI1的引脚设置是否正确。

　　3、设置FLASH的片选引脚即PC0引脚为输出模式，因为SPI1上只有一个器件，默认输出低电平。

五、生成代码

　　1、SPI1初始化代码如下所示：

static void MX_SPI1_Init(void)
{

  /* USER CODE BEGIN SPI1_Init 0 */

  /* USER CODE END SPI1_Init 0 */

  /* USER CODE BEGIN SPI1_Init 1 */

  /* USER CODE END SPI1_Init 1 */
  /* SPI1 parameter configuration*/
  hspi1.Instance = SPI1;
  hspi1.Init.Mode = SPI_MODE_MASTER;
  hspi1.Init.Direction = SPI_DIRECTION_2LINES;
  hspi1.Init.DataSize = SPI_DATASIZE_8BIT;
  hspi1.Init.CLKPolarity = SPI_POLARITY_LOW;
  hspi1.Init.CLKPhase = SPI_PHASE_1EDGE;
  hspi1.Init.NSS = SPI_NSS_SOFT;
  hspi1.Init.BaudRatePrescaler = SPI_BAUDRATEPRESCALER_8;
  hspi1.Init.FirstBit = SPI_FIRSTBIT_MSB;
  hspi1.Init.TIMode = SPI_TIMODE_DISABLE;
  hspi1.Init.CRCCalculation = SPI_CRCCALCULATION_DISABLE;
  hspi1.Init.CRCPolynomial = 10;
  if (HAL_SPI_Init(&hspi1) != HAL_OK)
  {
    Error_Handler();
  }
  /* USER CODE BEGIN SPI1_Init 2 */

  /* USER CODE END SPI1_Init 2 */

}

　　2、SPI1引脚及其相关的代码如下所示：

/**
* @brief SPI MSP Initialization
* This function configures the hardware resources used in this example
* @param hspi: SPI handle pointer
* @retval None
*/
void HAL_SPI_MspInit(SPI_HandleTypeDef* hspi)
{
  GPIO_InitTypeDef GPIO_InitStruct = {0};
  if(hspi->Instance==SPI1)
  {
  /* USER CODE BEGIN SPI1_MspInit 0 */

  /* USER CODE END SPI1_MspInit 0 */
    /* Peripheral clock enable */
    __HAL_RCC_SPI1_CLK_ENABLE();
  
    __HAL_RCC_GPIOA_CLK_ENABLE();
    /**SPI1 GPIO Configuration    
    PA5     ------> SPI1_SCK
    PA6     ------> SPI1_MISO
    PA7     ------> SPI1_MOSI 
    */
    GPIO_InitStruct.Pin = GPIO_PIN_5|GPIO_PIN_7;
    GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
    HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

    GPIO_InitStruct.Pin = GPIO_PIN_6;
    GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

  /* USER CODE BEGIN SPI1_MspInit 1 */

  /* USER CODE END SPI1_MspInit 1 */
  }

}

/**
* @brief SPI MSP De-Initialization
* This function freeze the hardware resources used in this example
* @param hspi: SPI handle pointer
* @retval None
*/
void HAL_SPI_MspDeInit(SPI_HandleTypeDef* hspi)
{
  if(hspi->Instance==SPI1)
  {
  /* USER CODE BEGIN SPI1_MspDeInit 0 */

  /* USER CODE END SPI1_MspDeInit 0 */
    /* Peripheral clock disable */
    __HAL_RCC_SPI1_CLK_DISABLE();
  
    /**SPI1 GPIO Configuration    
    PA5     ------> SPI1_SCK
    PA6     ------> SPI1_MISO
    PA7     ------> SPI1_MOSI 
    */
    HAL_GPIO_DeInit(GPIOA, GPIO_PIN_5|GPIO_PIN_6|GPIO_PIN_7);

  /* USER CODE BEGIN SPI1_MspDeInit 1 */

  /* USER CODE END SPI1_MspDeInit 1 */
  }

}

/**
  * @brief GPIO Initialization Function
  * @param None
  * @retval None
  */
static void MX_GPIO_Init(void)
{
  GPIO_InitTypeDef GPIO_InitStruct = {0};

  /* GPIO Ports Clock Enable */
  __HAL_RCC_GPIOC_CLK_ENABLE();
  __HAL_RCC_GPIOA_CLK_ENABLE();

  /*Configure GPIO pin Output Level */
  HAL_GPIO_WritePin(GPIOC, GPIO_PIN_0, GPIO_PIN_RESET);

  /*Configure GPIO pin : PC0 */
  GPIO_InitStruct.Pin = GPIO_PIN_0;
  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
  HAL_GPIO_Init(GPIOC, &GPIO_InitStruct);

}

六、编写与FLASH的相关代码

　　1、读一个字节

/**
  * @brief SPI1 读一个字节
  * @param None
  * @retval None
  */
static uint8_t spi1_flash_read_byte(void)
{
    uint8_t t_data, r_data;

    if(HAL_SPI_TransmitReceive(&hspi1, &t_data, &r_data, 1, 0xFFFFFF) != HAL_OK)
    {
        r_data = 0xff;
    }
    return r_data;
}

　　2、写一个字节

/**
  * @brief SPI1 写一个字节
  * @param byte 写入的字节
  * @retval 写状态 0成功 1失败
  */
static uint8_t spi1_flash_send_byte(uint8_t byte)
{
    uint8_t r_data;

    if(HAL_SPI_TransmitReceive(&hspi1, &byte, &r_data, 1, 0xFFFFFF) != HAL_OK)
    {
      return 1;
    }
    return 0;
}

　　3、FLASH写使能

/**
  * @brief FLASH 写使能
  * @param None
  * @retval None
  */
static void spi1_flash_write_enable(void)
{
    cs_low;
    spi1_flash_send_byte(0x06);
    cs_high;
}

　　4、FLASH等待写结束

/**
  * @brief FLASH 等待写结束
  * @param None
  * @retval None
  */
static void spi1_flash_wait_for_write_end(void)
{
  uint8_t state = 0;

  cs_low;

  spi1_flash_send_byte(0x05);

  do
  {
      state = spi1_flash_read_byte();
  }
  while((state & 0x01) == SET);

  cs_high;
}

　　5、读FLASH的ID

/**
  * @brief FLASH 读ID
  * @param None
  * @retval None
  */
uint32_t spi_flash_read_ID(void)
{
  uint32_t temp, temp0, temp1, temp2;

  cs_low;

  spi1_flash_send_byte(0x9F);

  temp0 = spi1_flash_read_byte();
  temp1 = spi1_flash_read_byte();
  temp2 = spi1_flash_read_byte();

  cs_high;

  temp = (temp0 << 16) | (temp1 << 8) | temp2;

  return temp;
}

　　6、读FLASH

/**
  * @brief 读FLASH
  * @param addr 读flash的起始地址
  * @param pdata 读到的数据存放起始地址
  * pdata size 读数据大小
  * @retval None
  */
void spi1_flash_read(uint32_t addr,uint8_t *pdata, uint16_t size)
{
  cs_low;

  spi1_flash_send_byte(0x03);

  spi1_flash_send_byte((addr & 0xFF0000) >> 16);
  spi1_flash_send_byte((addr & 0xFF00) >> 8);
  spi1_flash_send_byte(addr  & 0xFF);

  while (size--)
  {
    *pdata = spi1_flash_read_byte();
    pdata++;
  }

  cs_high;
}

　　7、按页写FLASH

/**
  * @brief 按页写FLASH
  * @param addr 写入flash的起始地址
  * @param pdata 写入数据的起始地址
  * pdata size 写数据大小
  * @retval None
  */
void spi1_flash_page_write(uint32_t addr, uint8_t *pdata, uint16_t size)
{
    uint16_t i;

    spi1_flash_write_enable();

    cs_low;

    spi1_flash_send_byte(0x02);
    spi1_flash_send_byte((uint8_t)((addr)>>16));
    spi1_flash_send_byte((uint8_t)((addr)>>8));
    spi1_flash_send_byte((uint8_t)addr);

    for(i = 0; i < size; i++)
    {
        spi1_flash_send_byte(pdata[i]);
    }

    cs_high;
    spi1_flash_wait_for_write_end();
}

　　8、写FLASH

/**
  * @brief 写FLASH
  * @param addr 写入flash的起始地址
  * @param pdata 写入数据的起始地址
  * pdata size 写数据大小
  * @retval None
  */
void spi1_flash_write(uint32_t addr, uint8_t *pdata, uint32_t size)
{
    uint32_t page_remain;

    page_remain = 256 - addr%256;

    if(size <= page_remain)
    {
        page_remain = size;
    }
    while(1)
    {
        spi1_flash_page_write(addr, pdata, page_remain);

        if(size == page_remain)
            break;
         else
        {
             pdata += page_remain;
             addr += page_remain;

             size -= page_remain;
            if(size > 256)
                page_remain = 256;
            else
                page_remain = size;
        }
    }
}

　　9、擦除FLASH扇区

/**
  * @brief 擦除FLASH扇区
  * @param sector_addr 扇区的起始地址
  * @retval None
  */
void spi1_flash_sector_erase(uint32_t sector_addr)
{
    spi1_flash_write_enable();
    spi1_flash_wait_for_write_end();

    cs_low;
    spi1_flash_send_byte(0x20);
    spi1_flash_send_byte((sector_addr & 0xFF0000) >> 16);
    spi1_flash_send_byte((sector_addr & 0xFF00) >> 8);
    spi1_flash_send_byte(sector_addr & 0xFF);

    cs_high;

    spi1_flash_wait_for_write_end();
}

　　10、擦除FLASH块

/**
  * @brief 擦除FLASH块
  * @param None
  * @retval None
  */
void spi1_flash_block_erase(void)
{
    spi1_flash_write_enable();

    cs_low;
    spi1_flash_send_byte(0xC7);
    cs_high;

    spi1_flash_wait_for_write_end();
}

#endif