6.6.2 Motorola 680x0 standard routine prologue / epilogue

Standard entry code for procedures and functions is as follows on the 680x0 architecture:

   move.l  a6,-(sp)  
   move.l  sp,a6

The generated exit sequence for procedure and functions looks as follows (in the default processor mode):

   unlk   a6  
   rtd    #xx

Where xx is the total size of the pushed parameters.

To have more information on function return values take a look at section 6.1, page 371.