ledtf0.asm

这些是基于dp51仿真仪的程序

SDA		EQU	P1.0
CLK		EQU	P1.1
LEDCS	        EQU	P1.7

COUNTER	        DATA    30H		;计数单元
DBUFFER		DATA	31H		;输出值

	ORG	4000H
	AJMP	MAIN

	ORG	4100H
MAIN:
	MOV	SP,#60H

	MOV	TMOD,#01H

	MOV	TH0,#3cH
	MOV	TL0,#0b0H
	MOV	COUNTER,#20
	MOV	DBUFFER,#80H
	SETB	TR0
LIUP:	
	JBC	TF0,LEDTF0
	MOV	R2,DBUFFER
	ACALL	TXDBYTE
	AJMP	LIUP
LEDTF0:	   CLR	   TR0	
	   MOV	   TH0,#3cH
	   MOV	   TL0,#0b0H
	   DJNZ	   COUNTER,LEDRET
	   MOV	   COUNTER,#20
	   MOV	   A,DBUFFER
	   RR	   A
	   MOV	   DBUFFER,A
LEDRET:    SETB	   TR0
	   AJMP	   LIUP
		   		   	
;若发送的数据存放在R2中
TXDBYTE:
	   PUSH	   PSW
	   PUSH	   ACC
	   SETB	   LEDCS
	   MOV	   A,R2	
	   MOV	   R3,#08H
TXDUP:	   RLC	   A
	   MOV	   SDA,C
	   CLR	   CLK
	   SETB	   CLK
	   DJNZ	   R3,TXDUP
	   CLR	   LEDCS
	   POP	   ACC
           POP	   PSW
	   RET
	   END