RTC实时时钟

最新推荐文章于 2024-09-20 11:21:37 发布

adlics_r

最新推荐文章于 2024-09-20 11:21:37 发布

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分类专栏：单片机实时时钟文章标签：单片机实时时钟

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在德飞莱的板子上，实时时钟应用的是DS1302芯片。
时钟外接晶振，可以算出最准确的一秒钟。

WP置低，写入；置高，读出


#define ds1302_sec_add          0x80        
#define ds1302_min_add          0x82        
#define ds1302_hr_add           0x84        
#define ds1302_date_add         0x86        
#define ds1302_month_add        0x88        
#define ds1302_day_add          0x8a        
#define ds1302_year_add         0x8c        
#define ds1302_control_add      0x8e        
#define ds1302_charger_add      0x90                     
#define ds1302_clkburst_add     0xbe

sbit SCK = P2^2;
sbit IO = P2^3;
sbit RST = P2^4;

void ds1302_write_byte(unsigned char addr, unsigned char byte)
{
      unsigned char i;
      addr = addr & 0xfe;
      SCK = 0;
      RST = 0;

      RST = 1;
      for(i = 0; i < 8; i++)
      {
               IO = addr & 0x01;
              SCK = 0;
              SCK = 1;
              addr >>= 1;
       }
      for(i = 0; i < 8; i++)
      {
               IO = byte & 0x01;
              SCK = 0;
              SCK = 1;
              byte >>= 1;
      }
}

unsigned char ds1302_read_byte(unsigned char addr)
{
      unsigned char i;
      unsigned char temp = 0;
      addr = addr & 0xfe;
      SCK = 0;
      RST = 0;

      RST = 1;
      addr =addr + 1;
      for(i = 0; i < 8; i++)
      {
               IO = addr & 0x01;
              SCK = 0;
              SCK = 1;
              addr >>= 1;
       }
       for(i = 0; i < 8; i++)
       {
              SCK = 1;
              SCK = 0;
              temp >>= 1;
              if(IO)
              {
                  temp += 0x80;
              }
        }
        RST = 0;
        return temp;
}
void ds1302_write_time()
{
      unsigned char temp;
      unsigned char temp1;
      unsigned char i;
      for(i = 0; i < 7; i++)
      {
              temp = timebuf[i]/10;
              temp1 = timebuf[i]%10;
              disbuf[i] = (temp << 4) | temp1;
      }
    ds1302_write_byte(ds1302_control_add, 0x00);
    ds1302_write_byte(ds1302_hr_add, disbuf[0]);
    ds1302_write_byte(ds1302_min_add, disbuf[1]);
    ds1302_write_byte(ds1302_sec_add, disbuf[2]);
    ds1302_write_byte(ds1302_year_add, disbuf[3]);
    ds1302_write_byte(ds1302_month_add, disbuf[4]);
    ds1302_write_byte(ds1302_date_add, disbuf[5]);
    ds1302_write_byte(ds1302_day_add, disbuf[6]);
    ds1302_write_byte(ds1302_control_add, 0x80);
}
void ds1302_read_time()
{
    unsigned char temp;
    unsigned char temp1;
    unsigned char i;
    readbuf[0] = ds1302_read_byte(ds1302_hr_add);
    readbuf[1] = ds1302_read_byte(ds1302_min_add);
    readbuf[2] = ds1302_read_byte(ds1302_sec_add);
    readbuf[3] = ds1302_read_byte(ds1302_year_add);
    readbuf[4] = ds1302_read_byte(ds1302_month_add);
    readbuf[5] = ds1302_read_byte(ds1302_date_add);
    readbuf[6] = ds1302_read_byte(ds1302_day_add);

    for(i = 0; i < 7; i++)
    {
        temp = readbuf[i]>>4;
        temp1 = readbuf[i]&0x0f;
        disbuf[i] = temp*10+temp1;
    }
}