PARM51 Compiler Directive

P51

None.

PARM251

Options — C251 Compiler — Object — C51 argument passing.

The PARM51 directive specifies that the compiler use the parameter passing conventions of the C51 compiler. This directive is useful when interfacing 251 programs to existing 8051 code.

Note

• You may switch between C51 and C251 parameter passing conventions any number of times in your source files.

PARM251

#pragma PARM51   /* switch to C51 calling conventions */
extern char *function_51 (char);     /*  C51 function */

#pragma PARM251 /* switch to C251 calling conventions */
extern char *function_251 (int);     /* C251 function */

pragma PARM51   /* switch to C51 calling conventions */

void f51 (char *p)  {    /* a C51 compatible function */
  *p = 0;
}

#pragma PARM251 /* switch to C251 calling conventions */

void main (void)  {
  char *p;
  p = function_51 (0);        /* call a C51 function  */
  p = function_251 (1);       /* call a C251 function */
}