单片机软件定时.doc

1秒定时程序

ORG 0000H
AJMP MAIN
ORG 000BH
LJMP CLK ;T0
MAIN: MOV TMOD,#51H
MOV IE,#00000010B
MOV TH0,#03CH
MOV TL0,#0B0H ;50mS
MOV 40H,#20
MOV 41H,#0
SETB TR0
SETB TR1
SETB EA
LOOP:NOP
JNB 70H,LOOP
CLR 70H
INC 41H
MOV P1,41H
AJMP LOOP
CLK: CLR TR0
MOV TH0,#3CH ;50mS
MOV TL0,#0B0H
SETB TR0
DJNZ 40H,CLE
MOV 40H,#20
SETB 70H
CLE: RETI

动态显示

XS3: MOV 78H,#0FEH
MOV 79H,#7CH
XS3LOP:MOV P2,#81H 位地址
MOV A,#0FFH
MOVX @R0,A
MOV R0,79H
MOV A,@R0
MOVC A,@A+DPTR
CPL A
MOV P2,#80H 段地址
MOVX @R0,A
MOV P2,#81H
MOV A,78H
MOVX @R0,A
RL A
MOV 78H,A
MOV R6,#10
LCALL DEL1 延迟
INC 79H
CJNE R0,#7FH,XS3LOP
RET

XS4: MOV R0,79H
MOV P2,#81H
MOV A,#0FFH
MOVX @R0,A
MOV A,@R0
MOVC A,@A+DPTR
CPL A
MOV P2,#80H
MOVX @R0,A
MOV P2,#81H
MOV A,78H
MOVX @R0,A
RL A
MOV 78H,A
INC 79H
CJNE R0,#7FH,XSE
MOV 79H,#7CH
MOV 78H,#0FEH
XSE: RET

小数点的显示

将显示小数点的位的段码置小数点有效
XS4: MOV R0,79H
MOV P2,#81H
MOV A,#0FFH
MOVX @R0,A
MOV A,@R0
MOVC A,@A+DPTR
CPL A
MOV P2,#80H
CJNE R0,#7DH,XSS
SETB ACC.7 ;共阴
XSS: MOVX @R0,A

MOV P2,#81H
MOV A,78H
MOVX @R0,A
RL A
MOV 78H,A
INC 79H
CJNE R0,#7FH,XSE
MOV 79H,#7CH
MOV 78H,#0FEH
XSE: RET

闪烁显示
闪烁位置，闪烁速度，闪烁条件,非显示代码替换正常代码
XS4: MOV R0,79H
MOV P2,#81H
MOV A,#0FFH
MOVX @R0,A
MOV A,@R0
MOVC A,@A+DPTR
CPL A
MOV P2,#80H
CJNE R0,#7DH,SS ;位置
JB 79H,SS ;条件
JB 78H,SS ;速度
MOV A,#0 ;共阴
XSS: MOVX @R0,A

MOV P2,#81H
MOV A,78H
MOVX @R0,A
RL A
MOV 78H,A
INC 79H
CJNE R0,#7FH,XSE
MOV 79H,#7CH
MOV 78H,#0FEH
XSE: RET