input.asm

这些是基于dp51仿真仪的程序

SDA		BIT	P1.0
CLK		BIT	P1.1
INPUT		BIT	P3.5
LED_CS		BIT	P1.7

	ORG	4000H
	AJMP	MAIN

	ORG	4100H
MAIN:
	MOV	SP,#60H
	SETB	INPUT
	clr	P1.7

UP:	JNB	INPUT,NEXTP
	MOV	R2,#00
	AJMP	NEXTPP
NEXTP:	MOV	R2,#0FFH	
NEXTPP:	ACALL	TXDBYTE
	AJMP	UP

;若发送的数据存放在R2中
TXDBYTE:
	   PUSH	   PSW
	   PUSH	   ACC
	   MOV	   A,R2	
	   MOV	   R3,#08H
TXDUP:	   RLC	   A
	   MOV	   SDA,C
	   CLR	   CLK
	   SETB	   CLK
	   DJNZ	   R3,TXDUP
	   POP	   ACC
           POP	   PSW
	   RET

	   END