74temp.asm

16位PIC单片机汇编语言编写模板1

;**********************************************************************
;   This file is a basic template file for assembly code generation   *
;   for the PICmicro PIC16C74. This file contains the basic code      *
;   building blocks to build upon.                                    *  
;                                                                     *
;   If interrupts are not used all code in the ORG 0x004 section can  *
;   be removed. In addition the variable assignments for 'w_temp'     *
;   and 'status_temp' can be removed.                                 *                            
;                                                                     *
;   Refer to the MPASM User's Guide for additional information on     *
;   features of the assembler (Document DS33014).   This document     *
;   can be obtained from the WEB site at www.micrcohip.com            *
;                                                                     *
;   Refer to the respective PICMicro data sheet for additional        *
;   information on the instruction set.                               *
;                                                                     *
;   Template file assembled with MPLAB V3.99.18 and MPASM V2.15.06.   *
;                                                                     *
;**********************************************************************
;                                                                     *
;    Filename:	    xxx.asm                                           *
;    Date:                                                            *
;    File Version:                                                    *
;                                                                     *
;    Author:                                                          *
;    Company:                                                         *
;                                                                     * 
;                                                                     *
;**********************************************************************
;                                                                     *
;    Files required:                                                  *
;                                                                     *
;                                                                     *
;                                                                     *
;**********************************************************************
;                                                                     *
;    Notes:                                                           *
;                                                                     *
;                                                                     *
;                                                                     *
;                                                                     *
;**********************************************************************


	list      p=16c74             ; list directive to define processor
	#include <p16c74.inc>         ; processor specific variable definitions

	__CONFIG   _CP_OFF & _WDT_OFF & _PWRTE_ON & _XT_OSC

; '__CONFIG' directive is used to embedd configuration data within .asm file.
; The lables following the directive are located in the respective .inc file.




;***** VARIABLE DEFINITIONS
w_temp        EQU     0x20        ; variable used for context saving 
status_temp   EQU     0x21        ; variable used for context saving








;**********************************************************************
		ORG     0x000             ; processor reset vector
		clrf    PCLATH            ; ensure page bits are claared
  		goto    main              ; go to beginning of program


		ORG     0x004             ; interrupt vector location
		movwf   w_temp            ; save off current W register contents
		movf	STATUS,w          ; move status register into W register
		clrf	STATUS            ; ensure file register bank set to 0
		movwf	status_temp       ; save off contents of STATUS register


; isr code can go here or be located as subroutines elsewhere


		clrf    STATUS            ; ensure file register bank set to 0
		movf    status_temp,w     ; retrieve copy of STATUS register
		movwf	STATUS            ; restore pre-isr STATUS register contents
		swapf   w_temp,f
		swapf   w_temp,w          ; restore pre-isr W register contents
		retfie                    ; return from interrupt


; remaining code goes here

main	







		END                       ; directive 'end of program'