实时时钟芯片DS1302的读写程序

51单片机第二十三课实时时钟芯片DS1302的读写

所属类别:课程代码发布日期:2011-03-05 点击量:385 #include

#include

#define uchar unsigned char

#define uint unsigned int

sbit sck=P1^0;

sbit io=P1^1;

sbit rst=P3^6;

sbit smgen=P2^3;

unsigned char code smg_du[]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f,0x77,0x7c,0x39,0x5e, 0x79,0x71,0x00,0x10};

unsigned char code smg_we[]={0x08,0x18,0x28,0x38,0x48,0x58,0x68,0x78};

uchar time_data[7]={10,6,4,17,11,58,30}; //年周月日时分秒

uchar write_add[7]={0x8c,0x8a,0x88,0x86,0x84,0x82,0x80};

uchar read_add[7]={0x8d,0x8b,0x89,0x87,0x85,0x83,0x81};

uchar disp[8];

void write_ds1302_byte(uchar dat);

void write_ds1302(uchar add,uchar dat);

uchar read_ds1302(uchar add);

void set_rtc(void);

void read_rtc(void);

void time_pros(void);

void display(void);

//************************************************

//延时函数，在12MHz的晶振频率下

//大约50us的延时

//************************************************

void delay_50us(uint t)

{

uchar j;

for(;t>0;t--)

for(j=19;j>0;j--);

}

//************************************************ //延时函数，在12MHz的晶振频率下

//大约50ms的延时

//************************************************ void delay_50ms(uint t)

{

uint j;

for(;t>0;t--)

for(j=6245;j>0;j--);

}

void write_ds1302_byte(uchar dat)

{

uchar i;

for(i=0;i<8;i++)

{

sck=0;

io=dat&0x01;

dat=dat>>1;

sck=1;

}

}

void write_ds1302(uchar add,uchar dat)

{

rst=0;

_nop_();

sck=0;_nop_();

rst=1;

_nop_();

write_ds1302_byte(add);

write_ds1302_byte(dat);

rst=0;

_nop_();

io=1;

sck=1;

}

uchar read_ds1302(uchar add)

{

uchar i,value;

rst=0;

_nop_();

sck=0;

_nop_();

rst=1;

_nop_();

write_ds1302_byte(add);

for(i=0;i<8;i++)

{

value=value>>1;

sck=0;

if(io)

value=value|0x80;

sck=1;

}

rst=0;

_nop_();

sck=0;

_nop_();

sck=1;

io=1;

return value;

}

void set_rtc(void)

{

uchar i,j;

for(i=0;i<7;i++)

{

j=time_data[i]/10;

time_data[i]=time_data[i]%10;

time_data[i]=time_data[i]+j*16;

}

write_ds1302(0x8e,0x00); //去除写保护for(i=0;i<7;i++)

{

write_ds1302(write_add[i],time_data[i]); }

write_ds1302(0x8e,0x80); //加写保护

}

void read_rtc(void)

{

uchar i;

for(i=0;i<7;i++)

{

time_data[i]=read_ds1302(read_add[i]); }

}

void time_pros(void)

{

disp[0]=time_data[6]%16;

disp[1]=time_data[6]/16;

disp[2]=16;

disp[3]=time_data[5]%16;

disp[4]=time_data[5]/16;

disp[5]=16;

disp[6]=time_data[4]%16;

disp[7]=time_data[4]/16;

}

void display(void)

{

uchar i;

for(i=0;i<8;i++)

{

P1=smg_du[disp[i]];

P2=smg_we[i];

delay_50us(20);

}

}

void main(void)

{

set_rtc();

delay_50us(20);