求教SPI的问题

寒灯

这两个函数没看懂
第一：u32 SPI_FLASH_ReadID(void)
{
  u32 Temp = 0, Temp0 = 0, Temp1 = 0, Temp2 = 0;
  /* Select the FLASH: Chip Select low */
  SPI_FLASH_CS_LOW();
  /* Send "RDID " instruction */
  SPI_FLASH_SendByte(W25X_JedecDeviceID);
  /* Read a byte from the FLASH */
  Temp0 = SPI_FLASH_SendByte(Dummy_Byte);
  /* Read a byte from the FLASH */
  Temp1 = SPI_FLASH_SendByte(Dummy_Byte);
  /* Read a byte from the FLASH */
  Temp2 = SPI_FLASH_SendByte(Dummy_Byte);
  /* Deselect the FLASH: Chip Select high */
  SPI_FLASH_CS_HIGH();
  Temp = (Temp0 << 16) | (Temp1 << 8) | Temp2;
  return Temp;
}


第二：u32 SPI_FLASH_ReadDeviceID(void)
{
  u32 Temp = 0;
  /* Select the FLASH: Chip Select low */
  SPI_FLASH_CS_LOW();
  /* Send "RDID " instruction */
  SPI_FLASH_SendByte(W25X_DeviceID);
  SPI_FLASH_SendByte(Dummy_Byte);
  SPI_FLASH_SendByte(Dummy_Byte);
  SPI_FLASH_SendByte(Dummy_Byte);
  
  /* Read a byte from the FLASH */
  Temp = SPI_FLASH_SendByte(Dummy_Byte);
  /* Deselect the FLASH: Chip Select high */
  SPI_FLASH_CS_HIGH();
  return Temp;
}

新手，求理解

红思雨

读厂商ID和设备ID，就是发两个不同的命令，接收芯片发回来的ID序列号，具体看看datasheet

寒灯

强烈支持，非常感谢哥们