spi_ee.c

STR73X演示软件

*                  - WriteAddr : EEPROM's internal address to write to.
*                  - NumByteToWrite : number of bytes to write to the EEPROM,
*                    must be equal or less than "SPI_PageSize" value. 
* Output         : None
* Return         : None
*******************************************************************************/
void SPI_EE_PageWrite(u8* pBuffer, u16 WriteAddr, u8 NumByteToWrite)
{
  /* enable the write access to the EEPROM */
  BSPI_EE_WriteEnable();		
    
  /* select the EEPROM */
  BSPI_EE_ChipSelect(Low);	   

  /* send "Write to Memory " instruction */    
  Send_Byte(WRITE);	
    
  /* send the high byte of the EEPROM's internal address to write to */
  Send_Byte(WriteAddr >> 8);  
    
  /* send the low byte of the EEPROM's internal address to write to */
  Send_Byte(WriteAddr & 0xFF);             
	               	    
  while(NumByteToWrite--) /* while there is data to be written */
  {
    /* send the current byte */			
    Send_Byte(*pBuffer); 	           
    
    /* point to the next byte to be written */
    pBuffer++; 
  }		
 
  /* deselect the EEPROM */
  BSPI_EE_ChipSelect(High);
  
  /* waiting loop until write opertaion has completed */
  BSPI_EE_WaitForLastTask();
}

/*******************************************************************************
* Function Name  : SPI_EE_BufferRead
* Description    : Reads a block of data from the EEPROM.
* Input          : - pBuffer : pointer to the buffer that receives the data read 
*                    from the EEPROM.
*                  - ReadAddr : EEPROM's internal address to read from.
*                  - NumByteToRead : number of bytes to read from the EEPROM.
* Output         : None
* Return         : None
*******************************************************************************/
void SPI_EE_BufferRead(u8* pBuffer, u16 ReadAddr, u16 NumByteToRead)
{
  /* select the EEPROM */
  BSPI_EE_ChipSelect(Low);	   
  
  /* send "Read from Memory " instruction */
  Send_Byte(READ);	 
  
  /* send the high byte of the EEPROM's internal address to read from */	
  Send_Byte(ReadAddr >> 8); 

  /* send the low byte of the EEPROM's internal address to read from */   
  Send_Byte(ReadAddr & 0xFF);     
    	
  while(NumByteToRead--) /* while there is data to be read */
  {
    /* read a byte from the EEPROM */			
    *pBuffer = Send_Byte(Dummy_Byte);
    
    /* point to the next location where the byte read will be saved */
    pBuffer++;
  }	
  
  /* deselect the EEPROM */
  BSPI_EE_ChipSelect(High);		
}

/*******************************************************************************
* Function Name  : SPI_EE_DMABufferRead
* Description    : Reads a block of data from the EEPROM. This function use the 
*                  DMA0 stream0 to store the data received by the BSPI2.
* Input          : - pBuffer : pointer to the buffer that receives the data read 
*                    from the EEPROM.
*                  - ReadAddr : EEPROM's internal address to read from.
*                  - NumByteToRead : number of bytes to read from the EEPROM.
* Output         : None
* Return         : None
*******************************************************************************/
void SPI_EE_DMABufferRead(u8* pBuffer, u16 ReadAddr, u16 NumByteToRead)
{
  DMA_InitStructure.DMA_BufferSize = NumByteToRead;
  DMA_InitStructure.DMA_DSTBaseAddr = (u32)pBuffer;

  DMA_Init(DMA0, &DMA_InitStructure);

  /* select the EEPROM */
  BSPI_EE_ChipSelect(Low);	   
  
  /* send "Read from Memory " instruction */
  Send_Byte(READ);	 
  
  /* send the high byte of the EEPROM's internal address to read from */	
  Send_Byte( ReadAddr >> 8); 

  /* send the low byte of the EEPROM's internal address to read from */   
  Send_Byte(ReadAddr & 0xFF);     
  
  /* purge the receive FIFO */
  BSPI_RxFifoDisable(BSPI2);

  /* enable DMA0 stream0 */
  DMA_Cmd(DMA0, DMA_Stream0, ENABLE);
  
  /* enable BSPI2 DMA interface */
  BSPI_DMACmd(BSPI2, ENABLE);
  	
  while(NumByteToRead--) /* while there is data to be read */
  {
    /* send byte through the BSPI2 peripheral */	
    BSPI_WordSend(BSPI2, Dummy_Byte); 	
  
    /* loop while Transmit FIFO is full */
    while(BSPI_FlagStatus(BSPI2, BSPI_FLAG_TFF) == SET);  
  }	
  
  /* deselect the EEPROM */
  BSPI_EE_ChipSelect(High);	
    
  /* disable BSPI2 DMA interface */
  BSPI_DMACmd(BSPI2, DISABLE);		
}
 
/*******************************************************************************
* Function Name  : SPI_EE_Erase
* Description    : Fills the whole memory with value 0xFF. This will set the  
*                  memory to its initial delivery state.
* Input          : None
* Output         : None
* Return         : None
*******************************************************************************/
void SPI_EE_Erase()
{
  u8 PageIndex = 0, Counter = 0; 
  u16 PageAddr = 0;
  
  for(PageIndex = 32; PageIndex != 0; PageIndex--)
  {        	
    /* enable the write access to the EEPROM */
    BSPI_EE_WriteEnable();		
  
    /* select the EEPROM */
    BSPI_EE_ChipSelect(Low);
    
    /* send "Write to Memory " instruction */	   
    Send_Byte(WRITE);	
    
    /* send the high byte of the EEPROM's internal page address to write to */	
    Send_Byte(PageAddr >> 8); 
 
    /* send the low byte of the EEPROM's internal page address to write to */	
    Send_Byte(PageAddr &0xFF);   
      
    for(Counter = 32; Counter != 0; Counter--) /* Page write */
    { 				
      Send_Byte(0xFF); 	        
    }
    
    /* deselect the EEPROM */
    BSPI_EE_ChipSelect(High);	

    /* waiting loop until write opertaion has completed */
    BSPI_EE_WaitForLastTask(); 
    
    /* select the next page address to write to */
    PageAddr += 32;    	    
  }		
}

/*******************************************************************************
* Function Name  : SPI_EE_ReadStatus
* Description    : Returns the EEPROM's status register.
* Input          : None
* Output         : None
* Return         : EEPROM's status register value .
*******************************************************************************/
static u8 SPI_EE_ReadStatus()
{
  u8 EE_Status = 0;
	
  /* select the EEPROM */
  BSPI_EE_ChipSelect(Low);
	
  /* send "Read Status Register" instruction */
  Send_Byte(RDSR);
		
  /* send a dummy byte to generate the clock needed by the EEPROM 
  and put the value of the status register in EE_Status variable */
  EE_Status = Send_Byte(Dummy_Byte);

  /* deselect the EEPROM */
  BSPI_EE_ChipSelect(High);	
  
  /* return the status register value */		
  return (EE_Status);   
}

/*******************************************************************************
* Function Name  : BSPI_EE_ChipSelect
* Description    : Selects and deselects the EEPROM.
* Input          : State : level to be applied on the EEPROM's ChipSelect pin.
* Output         : None
* Return         : None
*******************************************************************************/
static void BSPI_EE_ChipSelect(u8 State)
{
  GPIO_BitWrite(GPIO5, GPIO_PIN_3, (BitAction)State);
}

/*******************************************************************************
* Function Name  : Send_Byte
* Description    : Sends a byte through the BSPI interface and return the  byte 
*                  received from the SPI bus.
* Input          : byte : byte to send.
* Output         : None
* Return         : The value of the received byte.
*******************************************************************************/
static u8 Send_Byte(u8 byte)
{
  /* send byte through the BSPI2 peripheral */	
  BSPI_WordSend(BSPI2, byte); 	
  
  /* loop while Transmit FIFO is full */
  while(BSPI_FlagStatus(BSPI2, BSPI_FLAG_TFF) == SET);   

  /* loop while Receive FIFO is empty */
  while(BSPI_FlagStatus(BSPI2, BSPI_FLAG_RFNE) == RESET);	
  
  /* return the byte read from the SPI bus */
  return(BSPI_WordReceive(BSPI2)); 	  
}

/*******************************************************************************
* Function Name  : BSPI_EE_WriteEnable
* Description    : Enables the write access to the EEPROM.
* Input          : None
* Output         : None
* Return         : None
*******************************************************************************/
static void BSPI_EE_WriteEnable()  
{
  /* select the EEPROM */	
  BSPI_EE_ChipSelect(Low);	
  
  /* send "Write Enable" instruction */
  Send_Byte(WREN);
  
  /* deselect the EEPROM */
  BSPI_EE_ChipSelect(High);	
}

/*******************************************************************************
* Function Name  : BSPI_EE_WaitForLastTask
* Description    : Polls the status of the Write In Progress (WIP) flag in the  
*                  EEPROM's status  register  and  loop  until write  opertaion
*                  has completed.  
* Input          : None
* Output         : None
* Return         : None
*******************************************************************************/
static void BSPI_EE_WaitForLastTask() 
{
  u8 EE_Status = 0;
  
  /* loop as long as the memory is busy with a write cycle */ 		
  do
  { 			 
    EE_Status = SPI_EE_ReadStatus();    																				
  } while((EE_Status & WIP_Flag) == Write_In_Progress);   	
}

/******************* (C) COPYRIGHT 2005 STMicroelectronics *****END OF FILE****/