sh605.a51

初学者开始学单片机不知从何入手

;定义端口
SCL EQU P1.0;
SDA EQU P1.1;
;开始信号的传递
START: 	CLR 	SCL;
SETB 	SDA;
ACALL 	DELAY;
SETB 	SCL;
ACALL 	DELAY;
CLR 	SDA;
ACALL 	DELAY;
CLR 	SCL;
RET;

;停止信号的传递
STOP: 	CLR 	SCL;
CLR 	SDA;
ACALL 	DELAY;
SETB 	SCL;
ACALL 	DELAY;
SETB 	SDA;
ACALL 	DELAY;
RET;

;发送一个字节
SEND: 	MOV 	R0, 	#08H;
SEND0: 	RLC 	A;
MOV 	C SDA ;
SETB 	SCL;
ACALL 	DELAY;
CLR 	SCL;
DJNZ 	R0,	SEND0;
SETB 	SDA;
RET;

;接收一个字节
REV: 	MOV 	R0, 	#08H;
REV0: 	SETB 	SCL;
MOV 	C SDA;
RLC 	A;
CLR 	SCL;
DJNZ 	R7, 	REV0;
RET;

;接收一个应答位
ACKC: 	SETB 	SCL;
ACALL 	DELAY;
MOV C, 	SDA;
CLR 	SCL;
RET;

;发送一个应答位
ACKS:	SETB 	SCL;
ACALL 	DELAY;
MOV 	C SDA;
CLR 	SCL;
RET;

;延时程序
DELAY: 	NOP;
NOP;
NOP;
RET;