/**
*\brief Erases the specified 64KB block of the serial firmware dataflash.
*
* \param pAt25 Pointer to an AT25 driver instance.
* \param address Address of the block to erase.
*
* \return 0 if successful; otherwise returns AT25_ERROR_PROTECTED if the
* device is protected or AT25_ERROR_BUSY if it is busy executing a command.
*/
unsigned char AT25D_EraseBlock(At25 *pAt25, unsigned int address)
{
unsigned char status;
unsigned char error;
assert(pAt25);
/* Check that the flash is ready and unprotected */
status = AT25D_ReadStatus(pAt25);
if ((status & AT25_STATUS_RDYBSY) != AT25_STATUS_RDYBSY_READY) {
TRACE_ERROR("AT25D_EraseBlock : Flash busy\n\r");
return AT25_ERROR_BUSY;
}
else if ((status & AT25_STATUS_SWP) != AT25_STATUS_SWP_PROTNONE) {
TRACE_ERROR("AT25D_EraseBlock : Flash protected\n\r");
return AT25_ERROR_PROTECTED;
}
/* Enable critical write operation */
AT25D_EnableWrite(pAt25);
/* Start the block erase command */
error = AT25_SendCommand(pAt25, AT25_BlockEraseCmd(pAt25), 4, 0, 0, address, 0, 0);
assert(!error);
/* Wait for transfer to finish */
AT25D_Wait(pAt25);
/* Poll the Serial flash status register until the operation is achieved */
AT25D_WaitReady(pAt25);
return 0;
}
/**
* \brief Erases all the content of the memory chip.
*
* \param pAt25 Pointer to an AT25 driver instance.
*
* \return 0 if the device has been unprotected; otherwise returns
* AT25_ERROR_PROTECTED.
*/
unsigned char AT25D_EraseChip(At25 *pAt25)
{
unsigned char status;
unsigned char error;
assert(pAt25);
/* Check that the flash is unprotected */
status = AT25D_ReadStatus(pAt25);
if ((status & AT25_STATUS_SWP) != AT25_STATUS_SWP_PROTNONE) {
return AT25_ERROR_PROTECTED;
}
/* Enable critical write operation */
AT25D_EnableWrite(pAt25);
/* Erase the chip */
error = AT25_SendCommand(pAt25, AT25_CHIP_ERASE_2, 1, 0, 0, 0, 0, 0);
assert(!error);
/* Wait for transfer to finish */
AT25D_Wait(pAt25);
/* Poll the Serial flash status register until the operation is achieved */
AT25D_WaitReady(pAt25);
return 0;
}
/**
* \brief Unprotects the contents of the serial flash device.
*
* \param pAt25 Pointer to an AT25 driver instance.
*
* \return 0 if the device has been unprotected; otherwise returns
* AT25_ERROR_PROTECTED.
*/
unsigned char AT25D_Unprotect(At25 *pAt25)
{
unsigned char status;
assert(pAt25);
/* Get the status register value to check the current protection */
status = AT25D_ReadStatus(pAt25);
if ((status & AT25_STATUS_SWP) == AT25_STATUS_SWP_PROTNONE) {
/* Protection already disabled */
return 0;
}
/* Check if sector protection registers are locked */
if ((status & AT25_STATUS_SPRL) == AT25_STATUS_SPRL_LOCKED) {
/* Unprotect sector protection registers by writing the status reg. */
AT25D_EnableWrite(pAt25);
AT25D_WriteStatus(pAt25, 0);
}
/* Perform a global unprotect command */
AT25D_EnableWrite(pAt25);
AT25D_WriteStatus(pAt25, 0);
/* Check the new status */
status = AT25D_ReadStatus(pAt25);
if ((status & (AT25_STATUS_SPRL | AT25_STATUS_SWP)) != 0) {
return AT25_ERROR_PROTECTED;
}
else {
return 0;
}
}
/**
* \brief Writes data at the specified address on the serial firmware dataflash. The
* page(s) to program must have been erased prior to writing. This function
* handles page boundary crossing automatically.
*
* \param pAt25 Pointer to an AT25 driver instance.
* \param pData Data buffer.
* \param size Number of bytes in buffer.
* \param address Write address.
*
* \return 0 if successful; otherwise, returns AT25_ERROR_PROGRAM is there has
* been an error during the data programming.
*/
unsigned char AT25D_Write(
At25 *pAt25,
unsigned char *pData,
unsigned int size,
unsigned int address)
{
unsigned int pageSize;
unsigned int writeSize;
unsigned char error;
unsigned char status;
assert(pAt25);
assert(pData);
/* Retrieve device page size */
pageSize = AT25_PageSize(pAt25);
/* Program one page after the other */
while (size > 0) {
/* Compute number of bytes to program in page */
writeSize = min(size, pageSize - (address % pageSize));
/* Enable critical write operation */
AT25D_EnableWrite(pAt25);
/* Program page */
error = AT25_SendCommand(pAt25, AT25_BYTE_PAGE_PROGRAM, 4,
pData, writeSize, address, 0, 0);
assert(!error);
/* Wait for transfer to finish */
AT25D_Wait(pAt25);
/* Poll the Serial flash status register until the operation is achieved */
AT25D_WaitReady(pAt25);
/* Make sure that write was without error */
status = AT25D_ReadStatus(pAt25);
if ((status & AT25_STATUS_EPE) == AT25_STATUS_EPE_ERROR) {
return AT25_ERROR_PROGRAM;
}
pData += writeSize;
size -= writeSize;
address += writeSize;
}
return 0;
}
