CARD_ReadEeprom

# CARD_ReadEepromAsync

## Syntax

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

## Arguments

src | Transfer source EEPROM address.
dst | Transfer destination memory address.
len | Length of data being read, in bytes.
callback | Completion callback function. Specify `NULL` when this is unnecessary. This callback is invoked from 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 reads data asynchronously from an EEPROM device. 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 end. 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

This function executes an asynchronous process using an internal thread. See the description of the `CARD_GetThreadPriority` function for more information on this thread.

## See Also

`CARD_IsBackupEeprom
CARD_WaitBackupAsync
CARD_GetResultCode
CARD_ReadEeprom
CARD_WriteEeprom
CARD_VerifyEeprom
CARD_WriteAndVerifyEeprom
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.
2004/08/18 Added description of PXI interrupts.
2004/07/28 Initial version.

CONFIDENTIAL