; ----------D1302充電程序---------------------------
CD:     LCALL    ST02           ; D1302充電程序
     MOV    A,#90H
     LCALL     WR02
      MOV    A,#0A5H
      LCALL  WR02
      RET
;---------------D1302寫秒程序---------------------------------------
WRCLOCK:      mov        r0,#blk1
           LCALL   ST02    ;  起動D1302
           MOV    A,#86H                       ;寫入日期
           lcall      wr02
           mov      a,@r0
           lcall     wr02                     
           lcall     stop
           lcall     st02
           inc       r0
           MOV    A,#84H                       ;寫入小時
           lcall      wr02
           mov      a,@r0
           lcall     wr02 
           lcall     stop
           lcall     st02
           inc       r0
           MOV       A,#82H                       ;寫入分
           lcall    wr02
           mov      a,@r0
           lcall     wr02 
           lcall     stop
           lcall     st02
           inc         r0
           MOV       A,#80H                       ;寫入秒
           lcall      wr02
           mov      a,@r0
           lcall     wr02 
       RET
;----------------D1302讀秒，分，時,年，月程序--------------
CSCLOCK1: LCALL   ST02         ;起動D1302
      MOV       A,#0BFH      ;BFH為讀D1302時間
      LCALL   WR02                  ;寫D1302
      MOV      R0,#NUM4       ;秒，分，時地址
LP:      LCALL  RD02           ;調讀D1302
      MOV      @R0,A
      DEC      R0
      CJNE      R0, #NUM0,LP
      LCALL  STOP            ;停止D1302
      RET
; ----------起動D1302子程序-------------------
ST02:      CLR      RST
      CLR      CLK
      SETB      RST
      RET
; -----------------寫D1302子程序------------------
WR02:      MOV     R3,#08H
LP02:      SETB     RST
      RRC     A
      MOV     IO,C
      CLR     CLK
      NOP
      SETB      CLK
      DJNZ     R3,LP02
      RET
; --------- 讀D1302子程序-----------------
RD02:      SETB     IO        ;     讀時鐘
      SETB     RST
      MOV     R6,#08H
      SETB     RST
LP021:  CLR     CLK
      MOV     C,IO
      RRC     A
     SETB     CLK
     DJNZ     R6,LP021
     RET
STOP:     CLR     RST           ;停止D1302
      NOP
      RET


 
#pragma cd db oe sb
#include <reg51.h>
#include <intrins.h>
#define byte unsigned char
#define word unsigned int
sbit clk=0x95;
sbit sio=0x96;
sbit rst=0x97;
byte code time1[]={0x37,0x34,0x10,0x20,9,5,2,0};/*秒、分、時、日、月、星期、年、控制*/
byte code number[]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x98};    /*0-9*/
byte disdata[4];
byte data time2[8];
/*=========================Ds1302 driver program begin=======================*/
byte si_char()            //read a byte from Ds1302
{                        //out status: clk=0
    byte i,rdata=0;
    sio=1;
    for(i=0;i<8;i++)
    {
        clk=1;
        rdata>>=1;
        clk=0;            //read data after falling egde
        if(sio)rdata|=0x80;
    }
    return rdata;
}
void so_char(byte wdata)//write a byte to Ds1302
{                        //out status: clk=1
    byte i;
    for(i=0;i<8;i++)
    {
        clk=0;
        sio=(bit)(wdata&1);
        wdata>>=1;
        clk=1;            //write data at rising edge
    }
}
void burstwrite(byte *wd)
{
    byte i;
    rst=0;
    clk=0;
    rst=1;
    so_char(0xbe);
    for(i=0;i<8;i++)so_char(wd[i]);
    rst=0;
}
void burstread(byte *rd)
{
    byte i;
    rst=0;
    clk=0;
    rst=1;
    so_char(0xbf);
    for(i=0;i<8;i++)*(rd+i)=si_char();
    rst=0;
}
void randomwrite(byte addr,byte wdata)
{
    rst=0;
    clk=0;
    addr=(addr<<1)|0x80;
    rst=1;
    so_char(addr);
    so_char(wdata);
    rst=0;
}
byte randomread(byte addr)
{
    byte rdata;
    rst=0;
    clk=0;
    addr=(addr*2)|0x81;
    rst=1;
    so_char(addr);
    rdata=si_char();
    rst=0;
    return rdata;
}
/*=========================Ds1302 driver program end=========================*/
void delay(word time)
{
    for(;time>0;time--);
}
void display()
{
    byte selbit=0xef,i;
    for(i=0;i<4;i++)
    {
        P0=selbit;
        P2=disdata[i];
        delay(250);
        selbit<<=1;
        P2=0xff;
    }
}
void main()
{
    byte temp;
    randomwrite(7,0x80);        //disable write protect
    burstwrite(time1);
    burstread(time2);
    _nop_();
    burstread(time2);
//    randomwrite(2,0x23);
    temp=randomread(2);
    _nop_();
    temp=randomread(2);
    while(1)
    {
        temp=randomread(2);
        disdata[0]=number[temp>>4];
        disdata[1]=number[temp&0xf];
        temp=randomread(1);
        disdata[2]=number[temp>>4];
        disdata[3]=number[temp&0xf];
        display();
    }
}