# WM_SetPortCallback

## C Specification

      #include <nitro/wm.h>

      WMErrCode WM_SetPortCallback(
              u16             port ,
              WMCallbackFunc  callback ,
              void*           arg
      );

## Arguments

port | Port number. Use a value from 0-15.
`callback` | Specifies the callback function to be called when receiving the communication frames. This callback is called from within the interrupt handler.
`arg` | Argument passed to the callback function.

## Return Values

Returns the results of the `WMErrCode` enumerated type process.

## Description

Sets the callback function that is called when the data for the specified port is received This is a synchronous function that promptly returns the `WM_ERRCODE_SUCCESS` return value when the process succeeds.

## See Also

`WM_SetMPDataToPort`, `WMPort`

## Revision History

06/08/2005 Added statement about callbacks being called from the interrupt handler.
03/02/2005 Added statement about range that can be specified with the port argument.
10/22/2004 Changed return value type.
08/11/2004 Initial version

CONFIDENTIAL