# PM_PrependPreSleepCallback

## C Specification

      #include <nitro/spi.h>

      void PM_PrependPreSleepCallback( PMSleepCallbackInfo* info );

## Arguments

info | Pointer to the structure that includes the information of the added callback.

## Return Values

None.

## Description

Registers callback when switching to sleep mode. Registered at end of callback list.

This function allows you to register multiple callbacks. The callback is defined by the void type function that gets one `void*` type argument, as:

> `typedef void (*PMSleepCallback)( void* );`

This callback is called from inside `PM_GoSleepMode()`.

For more information, please refer to `PM_AppendPreSleepCallback()`.

## See Also

`PM_Init, PM_GoSleepMode,
PM_AppendPreSleepCallback, PM_PrependPreSleepCallback,
PM_AppendPostSleepCallback, PM_PrependPostSleepCallback,
PM_DeletePreSleepCallback, PM_DeletePostSleepCallback,`
`PM_SetSleepCallbackInfo`

## Revision History

2005/09/14 `PM_SetSleepCallback` was changed to `PM_SetSleepCallbackInfo`.
06/02/2005 Clarified the Callback call origin.
10/06/2004 Initial version.