MSP430:实时时钟-DS1302

 /*
  * DS1302.h
  *
  *  Created on: 2013-11-27
  *      Author: Allen
  */

 #ifndef DS1302_H_
 #define DS1302_H_

 #include     <MSP430G2553.h>
 #include    "MyType.h"

 //时间结构体
 typedef struct
 {
     uchar year;    //00-99,前面自己加入20，比如读出13为2013
     uchar month;
     uchar date;
     uchar hour;
     uchar min;
     uchar sec;
     uchar week;
 }_calendar_obj;

 extern _calendar_obj calendar;    //日历结构体

 #define delay_time              0
 //DS1302地址定义
 #define ds1302_sec_add            0x80        //秒数据地址
 #define ds1302_min_add            0x82        //分数据地址
 #define ds1302_hr_add            0x84        //时数据地址
 #define ds1302_date_add            0x86        //日数据地址
 #define ds1302_month_add        0x88        //月数据地址
 #define ds1302_day_add            0x8a        //星期数据地址
 #define ds1302_year_add            0x8c        //年数据地址
 #define ds1302_control_add        0x8e        //控制数据地址
 #define ds1302_charger_add        0x90
 #define ds1302_clkburst_add        0xbe

 //SCLK:P2.3
 #define        SCLK_DIR        (P2DIR)
 #define        SCLK_OUT        (P2OUT)
 #define        SCLK_REN        (P2REN)
 #define        SCLK_PIN        (BIT3)

 #define        SCLK_UP            (Set_Bit(SCLK_REN,SCLK_PIN))
 #define        SCLK_DirOut        (Set_Bit(SCLK_DIR,SCLK_PIN))
 #define        SCLK_H            (Set_Bit(SCLK_OUT,SCLK_PIN))
 #define        SCLK_L            (Clr_Bit(SCLK_OUT,SCLK_PIN))

 //DS_SDA:P2.4
 #define        IO_DIR            (P2DIR)
 #define        IO_OUT            (P2OUT)
 #define        IO_IN            (P2IN)
 #define        IO_REN            (P2REN)
 #define        IO_PIN            (BIT4)

 #define        IO_UP            (Set_Bit(IO_REN,IO_PIN))
 #define        IO_DirOut        (Set_Bit(IO_DIR,IO_PIN))
 #define        IO_H            (Set_Bit(IO_OUT,IO_PIN))
 #define        IO_L            (Clr_Bit(IO_OUT,IO_PIN))

 #define        IO_DirIn        (Clr_Bit(IO_DIR,IO_PIN))
 #define        IO_Data            (Get_Bit(IO_IN,IO_PIN))

 //RST:P2.5
 #define        RST_DIR            (P2DIR)
 #define        RST_OUT            (P2OUT)
 #define        RST_IN            (P2IN)
 #define        RST_REN            (P2REN)
 #define        RST_PIN            (BIT5)

 #define        RST_UP            (Set_Bit(RST_REN,RST_PIN))
 #define        RST_DirOut        (Set_Bit(RST_DIR,RST_PIN))
 #define        RST_H            (Set_Bit(RST_OUT,RST_PIN))
 #define        RST_L            (Clr_Bit(RST_OUT,RST_PIN))

 void DS1302_Init(void);
 static void delay_us( unsigned int k );
 void ds1302_write_byte(uchar addr, uchar data);
 uchar ds1302_read_byte(uchar addr);
 void ds1302_write_time(uchar year,uchar month,uchar day,uchar hour,uchar min,uchar sec,uchar week);
 void ds1302_read_time(void);
 void ds1302_sendtime_uart(void);

 #endif

DS1302.h

 /*
  * DS1302.c
  *
  *  Created on: 2013-11-29
  *      Author: Allen
  */

 #include    "DS1302.h"
 #include     <MSP430G2553.h>
 #include    "uart.h"

 _calendar_obj calendar;

 void DS1302_Init(void)
 {
     SCLK_DirOut;
     RST_DirOut;
     IO_DirOut;
     SCLK_L;
     RST_L;
     delay_us();
     SCLK_H;
 }

 static void delay_us( unsigned int k )
 {
     while(k--)
     _nop();

 }

 //向DS1302写入一字节数据
 void ds1302_write_byte(uchar addr, uchar data)
 {
     uchar i;
     IO_DirOut;
     RST_H;                    //启动DS1302总线
     //写入目标地址：addr
     addr = addr & 0xFE;   //最低位置零，寄存器0位为0时写，为1时读
     for (i = ; i < ; i ++) {
         if (addr & 0x01) {
             IO_H;
             }
         else {
             IO_L;
             }
         SCLK_H;      //产生时钟
         delay_us(delay_time);
         SCLK_L;
         delay_us(delay_time);
         addr = addr >> ;
         }
     //写入数据：d
     for (i = ; i < ; i ++) {
         if (data & 0x01) {
             IO_H;
             }
         else {
             IO_L;
             }
         SCLK_H;      //产生时钟
         delay_us(delay_time);
         SCLK_L;
         delay_us(delay_time);
         data = data >> ;
         }
     RST_L;        //停止DS1302总线
 }

 //从DS1302读出一字节数据
 uchar ds1302_read_byte(uchar addr)
 {

     uchar i,temp;
     RST_H;                    //启动DS1302总线
     //写入目标地址：addr
     addr = addr | 0x01;    //最低位置高，寄存器0位为0时写，为1时读
     IO_DirOut;
     for (i = ; i < ; i ++)
     {
         if (addr & 0x01)
         {
             IO_H;
         }
         else
         {
             IO_L;
         }
         SCLK_H;      //产生时钟
         delay_us(delay_time);
         SCLK_L;
         delay_us(delay_time);
         addr = addr >> ;
     }
     //输出数据：temp
     IO_DirIn;
     for (i = ; i < ; i ++)
     {
         temp = temp >> ;
         if (IO_Data)
 //        if( P2IN & BIT4)
         {
             temp |= 0x80;
         }
         else
         {
             temp &= 0x7F;
         }
         SCLK_H;      //产生时钟
         delay_us(delay_time);
         SCLK_L;
         delay_us(delay_time);
         }
     RST_L;                    //停止DS1302总线
     return temp;
 }

 //向DS302写入时钟数据
 void ds1302_write_time(uchar year,uchar month,uchar day,uchar hour,uchar min,uchar sec,uchar week)
 {
     uchar temp=;
     ds1302_write_byte(ds1302_control_add,0x00);            //关闭写保护
     ds1302_write_byte(ds1302_sec_add,0x80);                //暂停时钟
     //ds1302_write_byte(ds1302_charger_add,0xa9);        //涓流充电

     temp=(year/<<)|(year%&0x0F);
     ds1302_write_byte(ds1302_year_add,);        //年

     temp=(month/<<)|(month%&0x0F);
     ds1302_write_byte(ds1302_month_add,temp);    //月

     temp=(day/<<)|(day%&0x0F);
     ds1302_write_byte(ds1302_date_add,temp);        //日

     temp=((hour/<<)|(hour%&0x0F))&0x3F;
     ds1302_write_byte(ds1302_hr_add,temp);        //时

     temp=(min/<<)|(min%&0x0F);
     ds1302_write_byte(ds1302_min_add,temp);        //分

     temp=(sec/<<)|(sec%&0x0F);
     temp=temp&0x7f;
     ds1302_write_byte(ds1302_sec_add,temp);        //秒

     temp=week;
     ds1302_write_byte(ds1302_day_add,temp);        //周

     ds1302_write_byte(ds1302_control_add,0x80);            //打开写保护
 }

 //从DS302读出时钟数据
 void ds1302_read_time(void)
 {
     uchar temp=;

     temp=ds1302_read_byte(ds1302_year_add);//年
     calendar.year=(temp>>)*+temp&0x0F; //年

     temp=ds1302_read_byte(ds1302_month_add);//月
     calendar.month=(temp>>)*+temp&0x0F;    //月

     temp=ds1302_read_byte(ds1302_date_add);//日
     calendar.date=((temp&0x70)>>)* + (temp&0x0F);  //日

     temp=ds1302_read_byte(ds1302_hr_add);//时
     calendar.hour=((temp&0x70)>>)* + (temp&0x0F);

     temp=ds1302_read_byte(ds1302_min_add);    //分
     calendar.min=((temp&0x70)>>)* + (temp&0x0F);    //分

     temp=(ds1302_read_byte(ds1302_sec_add))&0x7f;//秒，屏蔽秒的第7位，避免超出59,此位控制时钟是否开启
     calendar.sec=((temp&0x70)>>)* + (temp&0x0F);//秒，屏蔽秒的第7位，避免超出59

     temp=ds1302_read_byte(ds1302_day_add); //周
     calendar.week=(temp>>)*+temp&0x0F; //周
 }

 void ds1302_sendtime_uart(void)
 {

     uart_send_ch(calendar.year/+'');
     uart_send_ch(calendar.year%+'');
     uart_send_ch('-');
     uart_send_ch(calendar.month/+'');
     uart_send_ch(calendar.month%+'');
     uart_send_ch('-');
     uart_send_ch(calendar.date/+'');
     uart_send_ch(calendar.date%+'');
     uart_send_ch(' ');

     uart_send_ch(calendar.hour/+'');
     uart_send_ch(calendar.hour%+'');
     uart_send_ch(':');
     uart_send_ch(calendar.min/+'');
     uart_send_ch(calendar.min%+'');
     uart_send_ch(':');
     uart_send_ch(calendar.sec/+'');
     uart_send_ch(calendar.sec%+'');

     uart_send_ch(' ');
     uart_send_ch(calendar.week/+'');
     uart_send_ch(calendar.week%+'');

     uart_send_ch('\n');
 }

DS1302.c

运行很简单：

main：

DS1302_Init();
    ds1302_write_time(13,12,1,20,33,23,7);
    ds1302_read_time();
    ds1302_sendtime_uart();

注意：年份不需要20，只写后面两位，范围00-99，所以年份范围是2000-2099

如果需要读出时间：

ds1302_read_time();
    ds1302_sendtime_uart();

还是很好操作的，两个电源pin角，电池以及外接直流。

至于寄存器，时钟，细看SPEC吧

这里采取24小时制式。