CODE Example

CODE Example

Directives highlighted in this example are:

• code

Program Functional Description

This program demonstrates the utility of the code directive, which declares the beginning of a section of program code.

Commented Code Listing

list p=16f877 ;Select the device.

#include <p16f877.inc> ;Include standard header file

;for the selected device.

RST CODE H'0' ;The code section named RST

;is placed at H'0'. The

;instruction 'goto start' is

;placed in code section RST

goto start ;Jumps to the location labelled

;'start'.

INTRT CODE H'4' ;The code section named INTRT is

;placed at H'4'. The instruction

;'goto service_int' is placed in

;code section INTRT.

goto service_int ;Jumps to the location labelled

;'service_int'.

PGM CODE ;This is the begining of the

;code section named PGM. It is a

;relocatable code section since

;no absolute address is given

;along with directive 'CODE'.

start

clrw

goto $

CODE ;This is a relocatable code

nop ;section since no address is

; ;specified with the CODE

; ;directive.

;

;

service_int

retfie

end