Keil Logo

PARM51 Compiler Directive

Abbreviation

P51

Arguments

None.

Default

PARM251

µVision

Options — C251 Compiler — Object — C51 argument passing.

Description

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.
See Also

PARM251

Example
#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 */
}
  Arm logo
Important information

This site uses cookies to store information on your computer. By continuing to use our site, you consent to our cookies.

Change Settings

Privacy Policy Update

Arm’s Privacy Policy has been updated. By continuing to use our site, you consent to Arm’s Privacy Policy. Please review our Privacy Policy to learn more about our collection, use and transfers
of your data.