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電路圖
程序范例：
1。七段數碼管顯示器顯示1234循環
2。七段顯示器顯示0000〜9999（自動加1）循環
七段顯示器顯示1234循環:
范例一：7seg1.*
LIST
P=16F877,R=DEC
;
#INCLUDE
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
BSF
PORTCA,1
END
范例二：7seg11.*
LIST P=16F877,R=DEC
#INCLUDE
CBLOCK H'20'
ENDC
;
PORTSEG EQU PORTD
TRISEG EQU TRISD
PORTCA EQU PORTB
TRICA EQU TRISB
;
ORG 0
NOP
BANKSEL TRICA
MOVLW 0
MOVWF TRICA
MOVWF TRISEG
BANKSEL PORTCA
MOVLW 0XFF
MOVWF PORTCA
MAIN: MOVLW H'99'
MOVWF PORTSEG
MOVLW H'FE'
MOVWF PORTCA
CALL DELAY25
BSF PORTCA,0
;
MOVLW H'B0'
MOVWF PORTSEG
MOVLW H'FD'
MOVWF PORTCA
CALL DELAY25
BSF PORTCA,1
;
MOVLW H'A4'
MOVWF PORTSEG
MOVLW H'FB'
MOVWF PORTCA
CALL DELAY25
BSF PORTCA,2
;
MOVLW H'F9
MOVWF PORTSEG
MOVLW H'F7'
MOVWF PORTCA
CALL DELAY25
BSF PORTCA,3
GOTO MAIN
;
#INCLUDE
END
七段顯示器顯示0000〜9999（自動加1）循環
范例一：7seg2.*
LIST P=16F877,R=DEC
#INCLUDE
CBLOCK H'20'
R0,DB0,DB1
ENDC
;
PORTSEG EQU PORTD
TRISEG EQU TRISD
PORTCA EQU PORTB
TRICA EQU TRISB
;
ORG 0
NOP
BANKSEL TRICA
MOVLW 0
MOVWF TRICA
MOVWF TRISEG
BANKSEL PORTCA
MOVLW 0XFF
MOVWF PORTCA
ST: MOVLW 10
MOVWF R0
MOVLW 0
MOVWF DB0
MOVWF DB1
MAIN: MOVF DB0,0
CALL TABLE
MOVWF PORTSEG
MOVLW H'FE'
MOVWF PORTCA
CALL DELAY25
BSF PORTCA,0
;
SWAPF DB0,0
CALL TABLE
MOVWF PORTSEG
MOVLW H'FD'
MOVWF PORTCA
CALL DELAY25
MOVF DB1,0
ADDLW H'6'
BTFSS STATUS,1
GOTO MAIN
BCF STATUS,1
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