Pic16f877 七段数码管显示电路

程序范例：
1。七段数码管显示器显示1234循环
2。七段显示器显示0000～9999（自动加1）循环

七段显示器显示1234循环:

范例一：7seg1.*
LIST		P=16F877,R=DEC	;
#INCLUDE		<P16F877.INC>		MOVF	DB1,0
CBLOCK		H'20'		CALL	TABLE
DB0,DB1				MOVWF	PORTSEG
ENDC				MOVLW	H'FB'
;				MOVWF	PORTCA
PORTSEG EQU		PORTD		CALL	DELAY25
TRISEG EQU		TRISD		BSF	PORTCA,2
PORTCA EQU		PORTB	;
TRICA EQU		TRISB		SWAPF	DB1,0
;				CALL	TABLE
	ORG	0		MOVWF	PORTSEG
	NOP			MOVLW	H'F7'
	BANKSEL	TRICA		MOVWF	PORTCA
	MOVLW	0		CALL	DELAY25
	MOVWF	TRICA		BSF	PORTCA,3
	MOVWF	TRISEG		GOTO	MAIN
	BANKSEL	PORTCA	;
	MOVLW	0XFF	TABLE: ANDLW		H'0F'
	MOVWF	PORTCA		ADDWF	PCL
	MOVLW	H'12'	T1:	RETLW	H'C0'	;’0’
	MOVWF	DB1		RETLW	H'F9'	;’1’
	MOVLW	H'34'		RETLW	H'A4'	;’2’
	MOVWF	DB0		RETLW	H'B0'	;’3’
MAIN:	MOVF	DB0,0		RETLW	H'99'	;’4’
	CALL	TABLE		RETLW	H'92'	;’5’
	MOVWF	PORTSEG		RETLW	H'82'	;’6’
	MOVLW	H'FE'		RETLW	H'F8'	;’7’
	MOVWF	PORTCA		RETLW	H'80'	;’8’
	CALL	DELAY25		RETLW	H'90'	;’9’
	BSF	PORTCA,0		RETLW	H'88'	;’A’
;				RETLW	H'83'	;’B’
	SWAPF	DB0,0		RETLW	H'C6'	;’C’
	CALL	TABLE		RETLW	H'A1'	;’D’
	MOVWF	PORTSEG		RETLW	H'86'	;’E’
	MOVLW	H'FD'		RETLW	H'8E'	;’F’
	MOVWF	PORTCA	;
	CALL	DELAY25	#INCLUDE <DELAY25.INC>
	BSF	PORTCA,1	END