S4 BIT P2.7
S3 BIT P2.6
S2 BIT P2.5
S1 BIT P2.4
CLK BIT P0.0
DAT BIT P0.1
STR BIT P0.2
BUF BIT P1.0
ORG 0000H
AJMP MAIN
ORG 0003H
AJMP LOOP
ORG 000BH
AJMP L2
ORG 0100H
MAIN:
MOV IE,#83H
MOV TCON,#01H
MOV TMOD,#51H
MOV TH0,#0DCH
MOV TL0,#010H
MOV R0,#0
mov R3,#0
MOV R1,#0
MOV 51H,#0
L4:;判断中断计数的标志位,作相应的动作
CJNE R1,#1,T4
SETB BUF
ACALL L8
CLR BUF
SETB TR0
T4:
CJNE R1,#2,T2
SETB BUF
ACALL L8
CLR TR0
T2:
CJNE R1,#3,T3
CLR BUF
ACALL L8
MOV R1,#0
MOV R0,#0
MOV R3,#0
T3:;数据输出,四位输出
MOV A,R0
MOV B,#10
DIV AB
MOV R6,A
MOV A,B
SETB S2
SETB S1
SETB S3
CLR S4
ACALL L7
ACALL L8
MOV A,R6
SETB S4
CLR S3
ACALL L7
ACALL L8
MOV A,R3
MOV B,#10
DIV AB
MOV R4,A
MOV A,B
SETB S3
CLR S2
ACALL L7
ACALL L8
MOV A,R4
SETB S2
CLR S1
ACALL L7
ACALL L8
AJMP L4
L7:;按位取数据输出
MOV DPTR,#TAB
MOVC A,@A+DPTR
CPL A
L5:MOV R7,#8
CLR STR
L6:;8位数据的输出
RRC A
MOV DAT,C
NOP
CLR CLK
NOP
NOP
SETB CLK
DJNZ R7,L6
SETB STR
CLR STR
RET
L8:MOV R7,#50 ;延迟函数50.50
dip:MOV R5,#50
DJNZ R5,$;等待中断
DJNZ R7,DIP
RET
L2:;定时中断
INC R0
CJNE R0,#99,L3
MOV R0,#0
INC R3
CJNE R3,#60,L3
MOV R3,#0
L3:;付值语句
MOV TH0,#0DCH;定时初值
MOV TL0,#010H;定时初值
RETI; 返回函数
LOOP:;外部中断程序
INC R1
RETI;返回主函数
TAB:DB 0F5H,05H,0E3H,67H,17H,76H,0F6H,25H
DB 0F7H,77H
END
