wuzhongduan.asm

pic16f877a单片机程序

	LIST P=16F877A,R=HEX

	STATUS	  EQU	03h
    PORTB   EQU  06H
    PORTC   EQU  07H
	TRISB 	  EQU	86H
    TRISC   EQU	87H 
    TRISD   EQU  88H
    INTCON  EQU  0BH
    PIE1    EQU  8CH
    PCLATH_TEMP  EQU 30H
    STATUS_TEMP  EQU 40H
    W_TEMP  EQU   50H
	PCLATH   EQU 0AH
    OPTION_REG  EQU  81H
    DATA1   EQU  30H
    DATA2   EQU  40H
   
    INTF  EQU      1
    GIE   EQU      7
    RBIE  EQU      3
	INTE   EQU      4
    INTEDG  EQU    6
    RP1	EQU	     6	;6,5 bit of STATUS
	RP0		EQU      5

	ORG		0X00
    NOP
   	GOTO	MAIN        
;====********  
MAIN
   BSF STATUS,RP0
   BCF STATUS,RP1
   MOVLW 00H
   MOVWF TRISC;先将C口设置为输出
   BCF STATUS,RP0
   CLRF PORTC
   BSF STATUS,RP0
   MOVLW 0E0H;将C0-C4设置为输出,C5-C7设置为输入
   MOVWF TRISC
   MOVLW 0FFH;将D0-D7设置为输入
   MOVWF TRISD
   MOVLW 03H
   MOVWF TRISB;将B0和B1设置为输入
  ; CLRF PIE1;  禁止PIE1对应的中断源
XUNHUAN 
   BCF STATUS,RP0
   ;CLRF  PIR1；对外围中断标志寄存器清零
   ;BSF INTCON,INTE;外部INT/RB0引脚中断屏蔽位
   ;BSF INTCON,GIE;使能总中断
   MOVLW 11H;表示CE位置1，R/C位选择为转换，A0初始化12位转换，CS片选为低，12/8数字输出按12位输出
   MOVWF PORTC  
   GOTO DELAY
READ 
   BCF STATUS,RP0
   BSF PORTC,1
   GOTO READ
;====================================
DELAY      
           BCF STATUS,RP0
		    MOVLW   0FFH
		    MOVWF   DATA1
LP1       
           MOVLW    0FFH
           MOVWF    DATA2
LP2
           DECFSZ   DATA2,1
           GOTO     LP2
           DECFSZ   DATA1,1
           GOTO     LP1 
           GOTO    READ
;============================
   END