11.3 12位串行ad转换器接口.txt

<mcs-51单片机应用开发实用子程序>书上的程序

2543CS		EQU		P1.4
DATAO		EQU		P1.5
DATAI		EQU		P1.6
CLOCK		EQU		P1.7
ADRCMD		BYTE	7FH
ADOUTH		BYTE	7EH
ADOUTL		BYTE	7DH
START:
CLR		CLOCK					
CLR		2543CS						
MOV	R2,#08H
MOV	A,ADRCMD
TLC1:
MOV	C,DATAO
RRC		A
MOV	DATAI,C
SETB	CLOCK
NOP							
CLR		CLOCK
NOP
DJNZ	R2,TLC1					
MOV	ADOUTL,A
MOV	A,#00H
MOV	R2,#04H
TLC2:
MOV	C,DATAO
RRC		A
SETB	CLOCK					
NOP	
CLR		CLOCK
NOP	
DJNZ	R2,TLC2					
MOV	ADOUTH,A
SWAP	ADOUTH
SETB	2543CS
RET