stm32F103、GD32F103读写Nor Flash实战指南

 一、NOR Flash基础与硬件连接

1. NOR Flash简介
NOR Flash是一种非易失性存储器，支持随机访问和XIP（Execute In Place）特性，常用于存储固件代码、特定数据。典型型号如GD25Q128（128Mbit容量，SPI接口），其擦写寿命约10万次，适合嵌入式系统扩展存储。

2. GD32F103硬件设计
以SPI接口的GD25Q系列为例：
引脚连接：

GD32F103	Nor Flash
PB12	CS
PB13 (SPI_SCK)	SCLK
PB14 (SPI_MISO)	SO（Data Out）
PB15 (SPI_MOSI)	SI （Data IN）

 二、SPI外设配置与驱动开发

1. SPI初始化代码

void SPI_FLASH_Init(void)
{
  u32 temp;
  SPI_InitTypeDef  SPI_InitStructure;
  GPIO_InitTypeDef GPIO_InitStructure;
  
  /* Enable SPI1 and GPIO clocks */
  /*!< SPI_FLASH_SPI_CS_GPIO, SPI_FLASH_SPI_MOSI_GPIO, 
       SPI_FLASH_SPI_MISO_GPIO, SPI_FLASH_SPI_DETECT_GPIO 
       and SPI_FLASH_SPI_SCK_GPIO Periph clock enable */
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB | RCC_APB2Periph_GPIOD, ENABLE);

  /*!< SPI_FLASH_SPI Periph clock enable */
  RCC_APB1PeriphClockCmd(RCC_APB1Periph_SPI2, ENABLE);
 
  
  /*!< Configure SPI_FLASH_SPI pins: SCK */
  GPIO_InitStructure.GPIO_Pin = GPIO_FONT_SPI_SCK;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure.GPIO_Mode = GPIO_FONT_SPI_SCK_FLAG;
  GPIO_Init(GPIO_FONT_SPI, &GPIO_InitStructure);

  /*!< Configure SPI_FLASH_SPI pins: MISO */
  GPIO_InitStructure.GPIO_Pin = GPIO_FONT_SPI_MISO;
  GPIO_Init(GPIO_FONT_SPI, &GPIO_InitStructure);

  /*!< Configure SPI_FLASH_SPI pins: MOSI */
  GPIO_InitStructure.GPIO_Pin = GPIO_FONT_SPI_MOSI;
  GPIO_Init(GPIO_FONT_SPI, &GPIO_InitStructure);

  /*!< Configure SPI_FLASH_SPI_CS_PIN pin: SPI_FLASH Card CS pin */
  GPIO_InitStructure.GPIO_Pin = GPIO_FONT_SPI_NSS;
  GPIO_InitStructure.GPIO_Mode = GPIO_FONT_SPI_NSS_FLAG;
  GPIO_Init(GPIO_FONT_SPI, &GPIO_InitStructure);

  /* Deselect the FLASH: Chip Select high */
  SPI_FLASH_CS_HIGH();

  /* SPI1 configuration */
  // W25X16: data input on the DIO pin is sampled on the rising edge of the CLK. 
  // Data on the DO and DIO pins are clocked out on the falling edge of CLK.
  SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex;
  SPI_InitStructure.SPI_Mode = SPI_Mode_Master;
  SPI_InitStructure.SPI_DataSize = SPI_DataSize_8b;
  SPI_InitStructure.SPI_CPOL = SPI_CPOL_High;
  SPI_InitStructure.SPI_CPHA = SPI_CPHA_2Edge;
  SPI_InitStructure.SPI_NSS = SPI_NSS_Soft;
  SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_4;
  SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;
  SPI_InitStructure.SPI_CRCPolynomial = 7;
  SPI_Init(SPI2, &SPI_InitStructure);

  /* Enable SPI1  */
  SPI_Cmd(SPI2, ENABLE);
//temp = SPI_FLASH_ReadID(); 
}

根据temp = SPI_FLASH_ReadID()返回的值，可以判断Nor Flash的一些信息，比如型号、容量大小等。

 2. NOR Flash控制函数

发送一个字节数据或命令

u8 SPI_FLASH_SendByte(u8 byte)
{
  /* Loop while DR register in not emplty */
  while (SPI_I2S_GetFlagStatus(FONT_SPI, SPI_I2S_FLAG_TXE) == RESET);

  /* Send byte through the SPI1 peripheral */
  SPI_I2S_SendData(FONT_SPI, byte);

  /* Wait to receive a byte */
  while (SPI_I2S_GetFlagStatus(FONT_SPI, SPI_I2S_FLAG_RXNE) == RESET);

  /* Return the byte read from the SPI bus */
  return SPI_I2S_ReceiveData(FONT_SPI);
}

发送半字数据

u16 SPI_FLASH_SendHalfWord(u16 HalfWord)
{
  /* Loop while DR register in not emplty */
  while (SPI_I2S_GetFlagStatus(FONT_SPI, SPI_I2S_FLAG_TXE) == RESET);

  /* Send Half Word through the SPI1 peripheral */
  SPI_I2S_SendData(FONT_SPI, HalfWord);

  /* Wait to receive a Half Word */
  while (SPI_I2S_GetFlagStatus(FONT_SPI, SPI_I2S_FLAG_RXNE) == RESET);

  /* Return the Half Word read from the SPI bus */
  return SPI_I2S_ReceiveData(FONT_SPI);
}

 读取一个字节
 

u8 SPI_FLASH_ReadByte(void)
{
  return (SPI_FLASH_SendByte(Dummy_Byte));
}

 三、关键操作实现

 1. 数据读取（Read Data）

void SPI_FLASH_BufferRead(u8* pBuffer, u32 ReadAddr, u16 NumByteToRead)
{
  /* Select the FLASH: Chip Select low */
  SPI_FLASH_CS_LOW();

  /* Send "Read from Memory " instruction */
  SPI_FLASH_SendByte(W25X_ReadData);

  /* Send ReadAddr high nibble address byte to read from */
  SPI_FLASH_SendByte((ReadAddr & 0xFF0000) >> 16);
  /* Send ReadAddr medium nibble address byte to read from */
  SPI_FLASH_SendByte((ReadAddr& 0xFF00) >> 8);
  /* Send ReadAddr low nibble address byte to read from */
  SPI_FLASH_SendByte(ReadAddr & 0xFF);

  while (NumByteToRead--) /* while there is data to be read */
  {
    /* Read a byte from the FLASH */
    *pBuffer = SPI_FLASH_SendByte(Dummy_Byte);
    /* Point to the next location where the byte read will be saved */
    pBuffer++;
  }

  /* Deselect the FLASH: Chip Select high */
  SPI_FLASH_CS_HIGH();
}

 2. 扇区擦除（Sector Erase）

void SPI_FLASH_SectorErase(u32 SectorAddr)
{
  /* Send write enable instruction */
  SPI_FLASH_WriteEnable();
  SPI_FLASH_WaitForWriteEnd();
  /* Sector Erase */
  /* Select the FLASH: Chip Select low */
  SPI_FLASH_CS_LOW();
  /* Send Sector Erase instruction */
  SPI_FLASH_SendByte(W25X_SectorErase);
  /* Send SectorAddr high nibble address byte */
  SPI_FLASH_SendByte((SectorAddr & 0xFF0000) >> 16);
  /* Send SectorAddr medium nibble address byte */
  SPI_FLASH_SendByte((SectorAddr & 0xFF00) >> 8);
  /* Send SectorAddr low nibble address byte */
  SPI_FLASH_SendByte(SectorAddr & 0xFF);
  /* Deselect the FLASH: Chip Select high */
  SPI_FLASH_CS_HIGH();
  /* Wait the end of Flash writing */
  SPI_FLASH_WaitForWriteEnd();
}

3. 写数据

void SPI_FLASH_BufferWrite(u8* pBuffer, u32 WriteAddr, u16 NumByteToWrite)
{
  u8 NumOfPage = 0, NumOfSingle = 0, Addr = 0, count = 0, temp = 0;

  Addr = WriteAddr % SPI_FLASH_PageSize;
  count =