;DS1302时钟芯片
;说明：
;入口条件： 	日(30H) 月(31H) 年(32H)
;  	    	秒(30H) 分(31H) 时(32H)
;           	星期(30H)
;出口信息：	日(30H) 月(31H) 年(32H)
;		秒(30H) 分(31H) 时(32H)
;		星期(30H)
;影响资源：PSW、R7、A    堆栈需求： 6字节

DS_SCK	BIT	P1.6	
DS_RST	BIT	P3.5	
DS_IO	BIT	P1.7	
READ_HMS:			
	CLR	DS_IO	
	JB	DS_IO, READ_HMS_END	
	MOV	A, #81H	
	LCALL	DS_READ1	
	MOV	30H, A	
	MOV	A, #83H	
	LCALL	DS_READ1	
	MOV	31H, A	
	MOV	A, #85H	
	LCALL	DS_READ1	
	MOV	32H, A	
			
	CLR	DS_RST	
	MOV	A, 30H	
	CLR	C	
	SUBB	A, #60H	
	JC	READ_HMS_END	
	MOV	30H, #00H	
	LCALL	SET_HMS	
READ_HMS_END:			
	RET		
READ_WEEK:			
	CLR	DS_IO	
	JB	DS_IO, READ_WEEK_END	
	MOV	A, #8BH	
	LCALL	DS_READ1	
	MOV	32H, A	
READ_WEEK_END:			
	RET		
DS_SEND1:			
	CLR	DS_RST	
	CLR	DS_SCK	
	NOP		
	NOP		
	NOP		
	SETB	DS_RST	
	LCALL	DS_SEND	
	MOV	A, 10H	
	LCALL	DS_SEND	
	RET		
SET_YMD:			;去除写保护
	MOV	A, #8EH	
	MOV	10H, #00H	
	LCALL	DS_SEND1	
	MOV	A, #8CH	
	MOV	10H, 32H	
	LCALL	DS_SEND1	
	MOV	R0, #86H	
	MOV	R1, #30H	
	MOV	R6, #02H	
	LJMP	NEXT_WRITE_SP	
	RET		
SET_HMS:			;去除写保护
	MOV	A, #8EH	
	MOV	10H, #00H	
	LCALL	DS_SEND1	
			
	MOV	R0, #80H	
	MOV	R1, #30H	
	MOV	R6, #03H	
	LJMP	NEXT_WRITE_SP	
SET_WEEK:			
	MOV	A, #8EH	
	MOV	10H, #00H	
	LCALL	DS_SEND1	
	MOV	A, #8AH	
	MOV	10H, 30H	
	LCALL	DS_SEND1	
	RET		
NEXT_WRITE_SP:			
	MOV	A, R0	
	MOV	10H, @R1	
	LCALL	DS_SEND1	
	INC	R0	
	INC	R0	
	INC	R1	
	DJNZ	R6, NEXT_WRITE_SP	
	MOV	A, #8EH	;打上写保护
	MOV	10H, #80H	
	LCALL	DS_SEND1	
	CLR	DS_RST	
	RET		
NEXT_READ_SP:			
	MOV	A, R1	
	LCALL	DS_READ1	
	MOV	@R0, A	
	INC	R1	
	INC	R1	
	INC	R0	
	DJNZ	R6, NEXT_READ_SP	
	CLR	DS_RST	
	RET		
READ_YMD:			
	MOV	A, #8DH	
	LCALL	DS_READ1	
	MOV	32H, A	
	MOV	R1, #87H	
	MOV	R6, #02H	
	MOV	R0, #30H	
	LJMP	NEXT_READ_SP	
	RET		
DS_SEND:			;发命令
	MOV	R7, #08H	
NEXT_BIT:			
	NOP		
	NOP		
	NOP		
	RRC	A	
	MOV	DS_IO, C	
	SETB	DS_SCK	
	NOP		
	NOP		
	NOP		
	NOP		
	NOP		
	CLR	DS_SCK	
	NOP		
	NOP		
	NOP		
	NOP		
	NOP		
	DJNZ	R7, NEXT_BIT	
	RET		
DS_READ:			;收数据
	MOV	R7, #08H	
NEXT_BIT1:			
	NOP		
	NOP		
	NOP		
	MOV	C, DS_IO	
	RRC	A	
	SETB	DS_SCK	
	NOP		
	NOP		
	NOP		
	NOP		
	NOP		
	CLR	DS_SCK	
	NOP		
	NOP		
	NOP		
	NOP		
	NOP		
	DJNZ	R7, NEXT_BIT1	
	RET		
DS_READ1:			
	CLR	DS_RST	
	CLR	DS_SCK	
	NOP		
	NOP		
	NOP		
	SETB	DS_RST	
	LCALL	DS_SEND	
	LCALL	DS_READ	
	RET		

 
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