;
;//*DS1302 PIN:
;//*
;//* SCLK (Serial Clock Input) - SCLK is used to synchronize data movement on
;//* the serial interface. This pin has a 40k. internal pull-down resistor.
p1302SCLK	BIT	P1.2
;//* I/O (Data Input/Output) - The I/O pin is the bi-directional data pin for
;//* the 3-wire interface. This pin has a 40k. internal pull-down resistor.
p1302IO		BIT	P1.3
;//* RST (Reset) - The reset signal must be asserted high during a read or a
;//* write. This pin has a 40k.internal pull-down resistor.
p1302RST	BIT	P1.4

;//* DS1302	Command code
SecondWCom	EQU	0x80
SecondRDCom	EQU	0x81
MinuteWCom	EQU	0x82
MinuteRDCom	EQU	0x83
HourWCom	EQU	0x84
HourRDCom	EQU	0x85
DateWCom	EQU	0x86	;//* How much day of a month
DateRDCom	EQU	0x87
MonthWCom	EQU	0x88
MonthRDCom	EQU	0x89
DayWCom		EQU	0x8A	;//* How much day of a week
DayRDCom	EQU	0x8B
YearWCom	EQU	0x8C
YearRDCom	EQU	0x8D
;//*
ControlWCom	EQU	0x8E	;//* enable only 7 bit, 7bit=0 may operate all register
						;//* of DS1302
ControRDCom EQU 0x8F	;//* only 7bit availability, 0-6bit = 0
TrChaWCom	EQU	0x90	;//* This register controls the trickle charge
						;//* characteristics of the DS1302.
TrChaRDCom	EQU	0x91	;//* The trickle charge select (TCS) bits (bits 4-7)
						;//* control the selection of the trickle charger. In
						;//* order to prevent accidental enabling, only a
						;//* pattern of 1010 will enable the trickle charger.
CBurstWCom	EQU	0xBE	;//* The clock/calendar command byte specifies burst 
						;//* mode operation. In this mode the first eight
CBurstRDCom	EQU	0xBF	;//* clock/calendar registers can be consecutively read 
						;//* or written starting with bit 0 of address 0.
;//* DS1302 inside buffer command code(0-31)
DSBufWCom0	EQU	0xC0
DSBufRDCom0	EQU	0xC1
;//*  .
;//*  .
;//*  .
DSBufWCom30	EQU	0xFC
DSBuRDCom30 EQU 0xFD
DSBufBurWC	EQU	0xFE	;//* The RAM command byte specifies burst mode operation.
						;//* In this mode, the 31 RAM registers can be 
DSBufBurRDC	EQU	0xFF	;//* consecutively read or written starting with bit 0
						;//* of address 0.

;//* date and time buffer
vYearBuf	EQU	0x30
vMonthBuf	EQU	0x31
vDateBuf	EQU	0x32
vDayBuf		EQU	0x33
vHourBuf	EQU	0x34
vMinuteBuf	EQU	0x35
vSecondBuf	EQU	0x36

;//*
;//* **************************************************************
;//*
	ORG		0x0000
	AJMP	Start
	ORG		0x0030
Start:
	MOV		SP,		#0x60
    MOV     R0,     #0x7F
ClearRAM:
    MOV     @R0,    #0
    DJNZ    R0,     ClearRAM

    MOV   SCON, #0x50;
    MOV   TMOD, #0x21; //Timer0 - 16bit timer mode

    MOV   TL1,  #253;
    MOV   TH1,  #253;

    SETB  TR1
    SETB  TI

	NOP
	NOP

aaaa:
    NOP
    NOP
    JB    P1.7,   aaaa
    CLR   P1.0
    CLR   P1.1
    LCALL Delay1s
    SETB  P1.1
    SETB  P1.0
    LCALL Delay1s
    AJMP  aaaa


	LCALL	INITDS1302
	NOP
	NOP
Loop:
	LCALL   ReadTime
	NOP
    CLR     TI
    MOV     SBUF,  vYearBuf
    JNB     TI,    $

    CLR     TI
    MOV     SBUF,  vMonthBuf
    JNB     TI,    $

    CLR     TI
    MOV     SBUF,  vDateBuf
    JNB     TI,    $

    CLR     TI
    MOV     SBUF,  vDayBuf
    JNB     TI,    $

    CLR     TI
    MOV     SBUF,  vHourBuf
    JNB     TI,    $

    CLR     TI
    MOV     SBUF,  vMinuteBuf
    JNB     TI,    $

    CLR     TI
    MOV     SBUF,  vSecondBuf
    JNB     TI,    $
    MOV     R6,    #0
Del:
    MOV     R7,    #0
    DJNZ    R7,    $
    DJNZ    R6,    Del
    AJMP    Loop
	NOP
;	LCALL	WriteTime
	NOP
	NOP
	AJMP	$
;//* **************************************************************
;//* Get year month date hour minute second
;//*
ReadTime:
	MOV     A,	#YearRDCom
	LCALL   RDInfoFromDS1302
	MOV     vYearBuf,	A
	MOV     A,	#MonthRDCom
	LCALL   RDInfoFromDS1302
	MOV     vMonthBuf,	A
	MOV     A,	#DateRDCom
	LCALL   RDInfoFromDS1302
	MOV     vDateBuf,	A
	MOV     A,	#HourRDCom
	LCALL   RDInfoFromDS1302
	MOV     vHourBuf,	A
	MOV     A,	#MinuteRDCom
	LCALL   RDInfoFromDS1302
	MOV     vMinuteBuf,	A
	MOV     A,	#SecondRDCom
	LCALL   RDInfoFromDS1302
	MOV     vSecondBuf,	A
	MOV     A,	#DayRDCom
	LCALL   RDInfoFromDS1302
	MOV     vDayBuf,	A
	RET
;//* **************************************************************
;//* set year month date hour minute second
;//*
WriteTime:
	MOV     A,	#YearWCom
	MOV     B,	vYearBuf
	LCALL   WInfoToDS1302
	MOV     A,	#DateWCom
	MOV     B,	vDateBuf
	LCALL   WInfoToDS1302
	MOV     A,	#MonthWCom
	MOV     B,	vMonthBuf
	LCALL   WInfoToDS1302
	MOV     A,	#HourWCom
	MOV     B,	vHourBuf
	LCALL   WInfoToDS1302
	MOV     A,	#SecondWCom
	MOV     B,	vSecondBuf
	LCALL   WInfoToDS1302
	MOV     A,	#MinuteWCom
	MOV     B,	vMinuteBuf
	LCALL   WInfoToDS1302
	MOV     A,	#DayWCom
	MOV     B,	vDayBuf
	LCALL   WInfoToDS1302
	RET
;//* **************************************************************
;//* Function:	get byte from ds1302 register
;//* Input:		A(command code)
;//* Output:	A(data byte)
;//* Register:	A,R7
RDInfoFromDS1302:
	CLR		p1302RST
	NOP
	CLR     p1302SCLK
	NOP
	SETB    p1302RST
	NOP
	MOV     R7,	#0x08	;//* 8bits/byte
WNextComBit:
	RRC     A			;//* command code
	MOV     p1302IO,C
	NOP
	SETB    p1302SCLK
	NOP
	CLR     p1302SCLK
	DJNZ    R7,	WNextComBit
	MOV     R7,	#0x08	;//* 8bits/byte
RDNextDataBit:
	MOV     C,	p1302IO
	RRC     A
	SETB    p1302SCLK
	NOP
	CLR     p1302SCLK
	DJNZ    R7,	RDNextDataBit
	CLR     p1302RST
	RET
;//* **************************************************************
;//* Function:	set info to ds1302 register
;//* Input:		A(command code)
;//*			B(data byte)
;//* Register:	A,B,R7
WInfoToDS1302:
	CLR     p1302RST
	NOP
	CLR     p1302SCLK
	NOP
	SETB    p1302RST
	NOP
	MOV     R7,	#0x08
WrNextComBit:
	RRC     A			;//* command code
	MOV     p1302IO,C
	NOP
	SETB    p1302SCLK
	NOP
	CLR     p1302SCLK
	DJNZ    R7,	WrNextComBit
	MOV     A,	B
	MOV     R7,	#0x08
WNextDataBit:
	RRC     A			;//* data byte
	MOV     p1302IO,C
	NOP
	SETB    p1302SCLK
	NOP
	CLR     p1302SCLK
	DJNZ    R7,	WNextDataBit
	CLR     p1302RST
	RET

;//* **************************************************************
;//* Function:	initialization DS1302, set initial time
;//*
INITDS1302:
;//* COMMAND BYTE
;//* The command byte is shown in Figure 1. Each data transfer is 
;//* initiated by a command byte. The MSB(Bit 7) must be a logic 1.
;//* If it is 0, writes to the DS1302 will be disabled. Bit 6 specifies
;//* clock/calendar data if logic 0 or RAM data if logic 1. Bits 1
;//* through 5 specify the designated registers to be input or output,
;//* and the LSB (bit 0) specifies a write operation (input) if logic
;//* 0 or read operation (output) if logic 1. The command byte is always
;//* input starting with the LSB (bit 0).
;//* ADDRESS/COMMAND BYTE Figure 1
;//*  --------------------------------------------------
;//* |   7  |   6   |  5  |  4  |  3  |  2  |  1  |  0  |
;//*  --------------------------------------------------
;//* |      | RAM / |     |     |     |     |     | RD /|
;//* |   1  |   /   | A4  | A3  | A2  | A1  | A0  |  /  |
;//* |      | /  CK |     |     |     |     |     |/  W |
;//*  --------------------------------------------------
	MOV		A,	#SecondRDCom
	LCALL   RDInfoFromDS1302
	JNB		ACC.7,	DisableWrite
;//*
	MOV     A,	#YearWCom
	MOV     B,	#0x00		;//* 2000 year
	LCALL   WInfoToDS1302
;//*
	MOV     A,	#MonthWCom
	MOV     B,	#0x07		;//* 7 month
	LCALL   WInfoToDS1302
;//*
	MOV     A,	#DateWCom
	MOV     B,	#0x01		;//* 1 day
	LCALL   WInfoToDS1302
;//*
	MOV     A,	#HourWCom
	MOV     B,	#0x12		;//* 12 hour
	LCALL   WInfoToDS1302
;//*
	MOV		A,	#MinuteWCom
	MOV     B,	#0x00		;//* 0 minute
	LCALL   WInfoToDS1302
;//*
	MOV     A,	#SecondWCom
	MOV     B,	#0x00		;//* 0 second
	LCALL   WInfoToDS1302
;//*
    MOV     A,	#DayWCom
    MOV     B,	#0x07		;//* sunday
	LCALL   WInfoToDS1302
DisableWrite:
	MOV     A,	#SecondRDCom
	LCALL   RDInfoFromDS1302
	MOV     vSecondBuf,	A
	RET

Delay1s:
    MOV   R7,   #10
Delay:
    MOV   R6,   #0
Dela:
    MOV   R5,   #0
    DJNZ  R5,   $
    DJNZ  R6,   Dela
    DJNZ  R7,   Delay
    RET

	END