PIC单片机应用开发典型模块-第四章程序.doc

PIC 单片机应用开发典型模块_第四章程序

程序应用

#INCLUDE<P16F877.INC>

RTCC EQU 01H

PC EQU 02H

PCLATH EQU 0AH

TEMP0TIME EQU 20H ;方波次数

TEMP0CONST EQU 21H ;方波常数

TEMO0DOT EQU 22H ;方波点数

TEMP2CONST EQU 41H ;三角波常数

TEMP2 DOT EQU 42H ;三角波点数

TEMP2OUT EQU 43H ;三角波输出值

OPTION_R EQU 81H

WBU EQU 2FH ;W 暂存

SBU EQU 2EH ;STATUS 暂存

RCC EQU 0FAH ;最大频率常数

;------------------------------------------------------------------------------------------

------------

ORG 0

ORG 4 ;中断程序

MOVWF WBU

SWAPF WB0, 0

SWAPF STATUS, 0

MOVWF SBU

CALL SERV_INT

SWAPF SBU, 0

MOVWF STATUS

SWAPF WBU, 0

CALL INT

CALL INTPORT

CALL INTTMO

LOOP ;延时

NOP

NOP

GOTO LOOP

;------------------------------------------------------------------------------------------

------------

INT

CLRF TEMP1OUT

CLRF TEMP2OUT

MOVLW 03H

MOVWF TEMP0TIME

MOVWF TEMP0CONST

MOVWF TEMP2TIME

MOVWF TEMP2CONST

MOVLW 06H

MOVWF TEMP1TIME

BCF STATUS, 1

BCF STATUS, 5

CLRF PORTC

CLRF PORTD

BSF PORTE,1

BSF STATUS, 5

MOVLW 00H

MOVWF TRISD

MOVLW OF4H

MOVWF TRISC

;------------------------------------------------------------------------------------------

------------

INTTM0 ;定时器初始化

BSF STATUS, 5

MOVLW 80H

MOVWF OPTION_ R

BCF STATUS, 5

MOVLW 0A0H

;开放定时器中断

BTFSC INTCON，2

GOTO SERVRTCC

CLRF INTCON

BSF INTCON, 5

RETURN

SERVRTCC

MOVLW RCC

MOVWF RTCC

BCF INTCON，2

CALL OUTPUT