lh7a400_lcd_evb_eeprom_driver.c

sharp flash blob 的烧写代码

* Outputs: None
*
* Returns: Nothing
*
* Notes:
*
**********************************************************************/
/* write/erase protection */
void lcd_eeprom_lock(void)
{
   /* wait for SSP to be not busy */
   while (ssp_busy() )
      ;

   ssp_transmit(EE_WDS );
}

/**********************************************************************
*
* Function: lcd_eeprom_unlock
*
* Purpose:
*  Allow EEPROM write or erase commands to work
*
* Processing:
*  Wait for all pending SSP transmissions to complete. Transmit
*  the unlock command.
*
* Parameters: None
*
* Outputs: None
*
* Returns: Nothing
*
* Notes:
*  The EEPROM is locked on power-up. You must call this function
*  before attempting to write or erase the EEPROM.
*
**********************************************************************/
void lcd_eeprom_unlock(void)
{
   /* wait for SSP to be not busy */
   while (ssp_busy() )
      ;

   ssp_transmit(EE_WEN );
}

/**********************************************************************
*
* Function: lcd_eeprom_read
*
* Purpose:
*  Return an EEPROM word from a specifed address
*
* Processing:
*  Wait for the last SSP transaction to complete, and flush the 
*  receive FIFO. Send the read command bit sequence plus a 0 of
*  turn-around time, and then send a 0 to keep the chip select
*  active and shift in the data read back. Wait for the writes
*  to complete by polling the busy bit in the status register.
*  Read and discard the first word in the receive FIFO. Read
*  and return the EEPROM data that is in the SSP receive FIFO.
*
* Parameters:
*  adr: The address of the word to erase (0-63)
*
* Outputs: None
*
* Returns: 
*  0 if the address is out of range. Otherwise, return the
*  the word read.
*
* Notes:
*
**********************************************************************/
UNS_16 lcd_eeprom_read(INT_32 adr)
{
   if (adr < 0 || adr > EEPROM_ADR_MAX)
      return 0;

   /* wait for SSP to be not busy */
   while (ssp_busy() )
      ;

   /* flush the receive FIFO */
   while (ssp_receive_fifo_not_empty() )
      ssp_receive();
	
   /* 
   command and address is shifted left to account 
   for one bit clock cycle of 0 transmitted.
   */
   ssp_transmit(EE_READ(adr) << 1); 
   ssp_transmit(0);

   /* wait for transfer to complete */
   while (ssp_busy() )
      ;

   /* discard the first word in the buffer */
   ssp_receive();

   /* return the data read */
   return ssp_receive();
}

/**********************************************************************
*
* Function: lcd_eeprom_block_read
*
* Purpose:
*
* Processing:
*  If nwords is negative, return 0. If adr is out of range, return 0
*  If adr + nwords exceedes the number of words in the EEPROM, clip
*  nwords to the most words that can be read from the EEPROM starting
*  at the given start address of the block.
*  Wait for the last SSP transaction to complete, and flush the 
*  receive FIFO. Send the read command bit sequence plus a 0 of
*  turn-around time, and then send a 0 to keep the chip select
*  active and shift in the data read back. Wait for the 
*  read command transmission to the EEPROM to complete by
*  polling the SSP receive FIFO not empty bit in the status 
*  register. Read and discard the data returned on the read
*  command transmission. For every word to be read except 1,
*  send a 0 to request the next word and then read the current
*  word from the receive FIFO. Then read the last word from
*  the receive FIFO. Return nwords.
*
* Parameters:
*  adr:    the starting address of the block to read
*  buffer: an array for storing the SSP receive words
*  nwords: the number of words to read
*
* Outputs: 
*  buffer filled with nwords read from the EEPROM.
*
* Returns:
*  0 if adr or nwords are illegal. Otherwise, return the number of
*  words read.
*
* Notes:
*
**********************************************************************/
INT_32 lcd_eeprom_block_read(INT_32 adr, UNS_16 * buffer, INT_32 nwords)
{
   int i;
   
   if (nwords <= 0)
      return 0;

   if (adr < 0 || adr > EEPROM_ADR_MAX)
      return 0;
 
   if (adr + nwords > (EEPROM_ADR_MAX + 1) )
      nwords = EEPROM_ADR_MAX - adr + 1;

   /* wait for SSP to be not busy */
   while (ssp_busy() )
      ;

   /* flush the receive FIFO */
   while (ssp_receive_fifo_not_empty() )
      ssp_receive();
	
   /* 
   command and address is shifted left to account 
   for one bit clock cycle of 0 transmitted.
   */
   ssp_transmit(EE_READ(adr) << 1 );

   ssp_transmit(0);

   /* wait for transfer to complete */
   while (ssp_receive_fifo_not_empty() )
      ;

   /* discard the first word in the buffer */
   ssp_receive();

   /* 
   receive all words (an extra word is in the transmit
   FIFO to keep the chip select active
   */
   for (i = 1; i < nwords; i++)
   {
      ssp_transmit(0);

      *buffer++ = ssp_receive();
   }
   *buffer++ = ssp_receive();

   /* wait for SSP to be not busy */
   while (ssp_busy() )
      ;

   /* flush the receive FIFO */
   while (ssp_receive_fifo_not_empty() )
      ssp_receive();

   return nwords;
}


/**********************************************************************
*
* Function: lcd_eeprom_write
*
* Purpose:
*  Write a single EEPROM word at a specifed EEPROM address
*
* Processing:
*  Wait for the last SSP transaction to complete, and flush the 
*  receive FIFO. Send the write command bit sequence followed
*  by the data to write. Return the result of eeprom_busy_poll()
*
* Parameters:
*  data:                    The data to be written
*  adr:                     The address of the word to erase (0-63)
*  timeout_in_milliseconds: number of milliseconds to wait for erase
*                           operation to complete
*
* Outputs: None
*
* Returns:
*  0 if the write times out
*  1 if the write is successful
*
* Notes:
*  This command will fail if the EEPROM is locked.
*
**********************************************************************/
INT_32 lcd_eeprom_write(INT_32 adr, UNS_16 data, 
                      INT_32 timeout_in_milliseconds)
{
   if (adr < 0 || adr > EEPROM_ADR_MAX)
      return 0;

   /* wait for SSP to be not busy */
   while (ssp_busy() )
      ;

   /* flush the receive FIFO */
   while (ssp_receive_fifo_not_empty() )
      ssp_receive();


   ssp_transmit(EE_WRITE(adr) );
   ssp_transmit(data );

   return eeprom_busy_poll(timeout_in_milliseconds);
}

/**********************************************************************
*
* Function: lcd_eeprom_fill
*
* Purpose:
*  Fill the entire EEPROM with a specified data value
*
* Processing:
*  Wait for the last SSP transaction to complete, and flush the 
*  receive FIFO. Send the write all command bit sequence followed
*  by the data to write. Return the result of eeprom_busy_poll()
*
* Parameters: 
*  data:                    The data to be written
*  timeout_in_milliseconds: number of milliseconds to wait for erase
*                           operation to complete
*
* Outputs: None
*
* Returns: 
*  0 if the write times out
*  1 if the write is successful
*
* Notes:
*  This command will fail if the EEPROM is locked.
*
**********************************************************************/
INT_32 lcd_eeprom_fill(UNS_16 data, 
                     INT_32 timeout_in_milliseconds)
{
   /* wait for SSP to be not busy */
   while (ssp_busy() )
      ;

   /* flush the receive FIFO */
   while (ssp_receive_fifo_not_empty() )
      ssp_receive();

   ssp_transmit(EE_WRAL);
   ssp_transmit(data );

   return eeprom_busy_poll(timeout_in_milliseconds);
}