DS1302-演示代码

参考DS1302数据手册，尽管数据手册是英文，但是很有帮助，再结合网上众多的代码写出了下面这个例子，除了涓流充电（trickle charger）功能没使用外，内部的RAM和寄存器功能都使用到了，包括多字节方式（burst mode）。自认为我写的比网上大多数程序清晰，当然已经硬件测试过了。

 #include <reg52.h>

 /*DS1302部分*/

 //全部为写入地址，读取地址需要+1
 #define YEAR 0x8c
 #define MON 0x88
 #define DATE 0x86
 #define DAY 0x8a
 #define HOUR 0x84
 #define MIN 0x82
 #define SEC 0x80
 #define WP 0x8e
 #define RAM(n) (0xc0+2*(n))
 #define CLBT 0xbe
 #define RAMBT 0xfe

 //3个通信引脚
 sbit SCLK=P2^;
 sbit IO=P2^;
 sbit RST=P2^;    //有的使能端叫CE

 unsigned char readbyte(void);
 void writebyte(unsigned char dat);
 void write1302(unsigned char addr,unsigned char dat);
 unsigned char read1302(unsigned char addr);

 /*数码管部分，6位共阴接在P0*/
 sbit we=P2^;
 sbit du=P2^;
 void show(void);
 void delayms(unsigned time);

 unsigned char code table[] = {
 0x3f , 0x06 , 0x5b , 0x4f,
 0x66 , 0x6d , 0x7d , 0x07,
 0x7f , 0x6f , 0x77 , 0x7c,
 0x39 , 0x5e , 0x79 , 0x71,
 0x00 };

 unsigned char num[]={};    //用作数码管显示的数组

 /*键盘部分，4个独立键盘接在P3.4-P3.7*/
 void keyscan(void);
 bit showdate=;
 bit showday=;

 void main(void)
 {
     unsigned char temp;

     write1302(WP,0x00);    //允许写入，关闭写保护

     //clock burst 方式赋初值
     RST=;
     SCLK=;
     RST=;
     writebyte(CLBT);

     writebyte(0x30);//秒分时
     writebyte(0x59);
     writebyte(0x23);

     writebyte(0x28);//日月
     writebyte(0x02);

     writebyte(0x02);//星期

     writebyte(0x32);//年

     writebyte(0x00);
     writebyte(0x00);
     RST=;

 //    另一种赋初值方法
 //    write1302(HOUR,0x23);
 //    write1302(MIN,0x59);
 //    write1302(SEC,0x30);    

     while()
     {
         keyscan();
         if(showdate)
         {
             temp=read1302(YEAR+);
             num[]=temp>>;
             num[]=temp&0x0f;
             temp=read1302(MON+);
             num[]=temp>>;
             num[]=temp&0x0f;
             temp=showday?read1302(DAY+):read1302(DATE+);
             num[]=temp>>;
             num[]=temp&0x0f;
         }
         else
         {
             temp=read1302(HOUR+);
             num[]=temp>>;
             num[]=temp&0x0f;
             temp=read1302(MIN+);
             num[]=temp>>;
             num[]=temp&0x0f;
             temp=read1302(SEC+);
             num[]=temp>>;
             num[]=temp&0x0f;
         }
         show();
     }

 }

 unsigned char readbyte(void)
 {
     unsigned char i,ret;
     for(i=;i<;i++)
     {
         ret>>=;
         SCLK=;
         SCLK=;
         ret|=IO?0x80:0x00;
     }
     return ret;
 }

 void writebyte(unsigned char dat)
 {
     unsigned char i;
     for(i=;i<;i++)
     {
         IO=dat&;
         SCLK=;
         SCLK=;
         dat>>=;
     }
 }

 void write1302(unsigned char addr,unsigned char dat)
 {
     RST=;
     SCLK=;
     RST=;
     writebyte(addr);
     writebyte(dat);
     RST=;
 }

 unsigned char read1302(unsigned char addr)
 {
     unsigned char ret;
     RST=;
     SCLK=;
     RST=;
     writebyte(addr);
     ret=readbyte();
     RST=;
     return ret;
 }

 void show(void)
 {
     unsigned char i;

     for(i=;i<;i++)
     {
         P0=0xff;
         we=;
         we=;      

         P0=table[num[i]];
         du=;
         du=;

         P0=~(0x20>>i);
         we=;
         we=;

         delayms();
     }
 }

 void delayms(unsigned time)
 {
     unsigned i,j;

     for(i=time;i>;i--)
         for(j=;j>;j--)
         ;
 }

 void keyscan(void)
 {
     unsigned char temp;
     unsigned char reg[];

     if((P3|0x0f)!=0xff)
     {
         delayms();
         if((temp=P3|0x0f)!=0xff)
         {
             while((P3|0x0f)!=0xff);
             switch(temp)
             {
             case 0xef:    //显示时间还是日期
                 showdate=~showdate;
                 break;
             case 0xdf:    //日期最后两位显示日还是星期
                 showday=~showday;
                 break;
             case 0xbf:    //将时钟寄存器保存到RAM
                 RST=;
                 SCLK=;
                 RST=;
                 writebyte(CLBT+);
                 for(temp=;temp<;temp++)
                     reg[temp]=readbyte();
                 RST=;

                 //从20号RAM开始存入，起始RAM号随意，只要不超过范围即可
                 for(temp=;temp<;temp++)
                     write1302(RAM(+temp),reg[temp]);

                 /*    也可以用 RAM burst 写入
                 RST=0;
                 SCLK=0;
                 RST=1;
                 writebyte(RAMBT);
                 for(temp=0;temp<9;temp++)
                     writebyte(reg[temp]);
                 RST=0;
                 */

                 break;
             case 0x7f:    //从RAM恢复到时钟寄存器
                 /*    对应的 RAM burst 读取
                 RST=0;
                 SCLK=0;
                 RST=1;
                 writebyte(RAMBT+1);
                 for(temp=0;temp<9;temp++)
                     reg[temp]=readbyte();
                 RST=0;
                 */

                 for(temp=;temp<;temp++)
                     reg[temp]=read1302(RAM(+temp)+);

                 RST=;
                 SCLK=;
                 RST=;
                 writebyte(CLBT);
                 for(temp=;temp<;temp++)
                     writebyte(reg[temp]);
                 RST=;
                 break;
             }
         }
     }
 }

DS1302.c