# CARD_VerifyFlashAsync

## Syntax

  `#include <nitro/card.h>`
  `static inline void CARD_VerifyFlashAsync( u32 dst, const void *src, u32 len, MIDmaCallback callback, void *arg);`

## Arguments

dst | The FLASH address of the comparison target
src | Memory address of comparison source.
len | Byte length of data to be compared.
callback | Completion callback function. Specify `NULL` if this is unnecessary. This callback is called from within the interrupt handler.
arg | Arguments to pass to the completion callback function. This is simply ignored if `NULL` was specified for `callback`.

## Return Values

None.

## Description

This function asynchronously compares the data of the FLASH device with the designated memory. This function immediately returns control. To use this function, you must first lock the access bus with the `CARD_LockBackup` function. Use the `CARD_WaitBackupAsync` function to wait for processing to complete. To determine the processing result, call the `CARD_GetResultCode` function after processing is complete.
This function communicates with the ARM7 processor internally via PXI.
The process will not end if PXI interrupts are not enabled.

## Internal Operation

`The function uses an internal thread to execute an asynchronous process. See the description of the `CARD_GetThreadPriority` function for more information on this thread.`

## See Also

`CARD_IsBackupFlash
CARD_WaitBackupAsync
CARD_GetResultCode
CARD_ReadFlash
CARD_WriteFlash
CARD_VerifyFlash
CARD_WriteAndVerifyFlash
CARD_GetThreadPriority`

## Revision History

2005/06/01 Added a statement indicating that callback is called from interrupt handler.
2004/12/09 Changed "IO processor" to "ARM7 processor".
2004/11/02 Revised links.
2004/08/23 Revised links due to function changes.
2004/08/18 Initial version.

CONFIDENTIAL