AT89C2051+LCD1602+DS1302 Real-time Clock Design (c51)

#include
#define uchar unsigned char
sbit rs=P3^0;//LCD1602控制脚
sbit rw=P3^1;
sbit e=P3^2;

sbit io=P3^4; //DS1302 PCI bus pin
sbit rst=P3^5;
sbit sclk=P3^3;

uchar hour,minute,second,year,months,date,day; //Display time register
uchar whour,wminute,wsecond,wyear,wmonths,wdate,wday; //Set initial time register
uchar code table1[]="0123456789-:w";
uchar code table2[]="Date:20";
uchar code table3[]="Time:";

void delayms(uchar k)//1ms延时
{
 uchar j,i;
 for(i=0;i   for(j=0;j<120;j++); 
}

void delay2us() //2us delay
{
 _nop_();
 _nop_();
}

void write1602_data(uchar dat)//1602 write data subroutine
{
 rs=1;
 rw=0;
 P1=dat;
 delayms(2);
 e=0;
 e=1;
 e=0; 
}

void write1602_com(uchar com) //1602 write command subroutine
//
{
 rs=0;
 rw=0;
 P1=com;
 delayms(5);
 e=0;
 e=1;
 e=0;
}

void init1602() //1602 initialization subroutine
{
 write1602_com(0x38); //lcd1602 16*2 display, 5*7 dot matrix, 8bit data interface
 write1602_com(0x0f); //turn on the display, display the cursor, and the cursor flashes
 write1602_com(0x06); //When a character is written, the address pointer increases by one, and the cursor increases by one
 write1602_com(0x01); //clear the screen
}

void disptop() //1602 first line display subroutine
{
 uchar i;
 write1602_com(0x80);
 for(i=0;i<0x07;i++)
 {
  write1602_data(table2[i]);
  delayms(1);
 }
}

void dispbot() //1602 second line display subroutine
{
 uchar i;
 write1602_com(0xc0);
 for(i=0;i<0x05;i++)
 {
  write1602_data(table3[i]);
  delayms(1);
 }
}

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

void write1302byte(uchar dat)//1302 writes a byte Subroutine
{
 uchar i;
 sclk=0;
 for(i=0;i<8;i++)
 {
  io=(bit)(dat&0x01);
  delay2us();
  sclk=1;
  delay2us();
  sclk=0;
  dat=dat>>1;
 } 
}

uchar read1302byte() //1302 reads a byte subroutine
{
 uchar i,dat;
 for(i=0;i<8;i++)
 {
  dat>>=1;
  if(io)
  dat|=0x80;
  delay2us();
  sclk=1;
  delay2us();
  sclk=0;
  delay2us();  
 }
 return dat;  
}

void writeset1302(uchar add,uchar dat)//1302 read child program
{
 rst=0;
 delay2us();
 rst=1;            
 write1302byte(add);
 write1302byte(dat);
 rst=0;
}

uchar readset1302(uchar add)//1302写子电影
{
 uchar dat;
 rst=0;
 delay2us();
 rst=1;
 write1302byte(add);
 dat=read1302byte();
 rst=0;
 return dat;
}

void init1302() //1302 initialization subroutine
{
 uchar flag;
 flag=readset1302(0x81); //Judge whether 1302 has a backup battery, if yes, FLAG is 0
 if(flag&0x80)
 {
  writeset1302(0x8e,0x00);
  writeset1302(0x80,((wsecond/10)<<4|(wsecond%10)));
  writeset1302(0x82,((wminute/10)<<4|(wminute%10)));
  writeset1302(0x84,((whour/10)<<4|(whour%10)));
  writeset1302(0x86,((wday/10)<<4|(wday%10)));
  writeset1302(0x88,((wmonths/10)<<4|(wmonths%10)));
  writeset1302(0x8a,((wdate/10)<<4|(wdate%10)));
  writeset1302(0x8c,((wyear/10)<<4|(wyear%10)));
  writeset1302(0x90,0xa5);
  1302(0x8e,0x80);
 } 
}

uchar readvalue(uchar value) //data conversion
{
 uchar a;
 a=((value&0x70)>>4)*10+(value&0x0f);
 return a; 
}

void read1302()    //读取时间
{
 uchar value;
 value=readset1302(0x81);
 second=readvalue(value);
 
 value=readset1302(0x83);
 minute=readvalue(value);
 
 value=readset1302(0x85);
 hour=readvalue(value);
 
 value=readset1302(0x87);
 day=readvalue(value);
 
 value=readset1302(0x89);
 months=readvalue(value);

 value=readset1302(0x8b);
 date=readvalue(value);

 value=readset1302(0x8d);
 year=((value&0xf0)>>4)*10+(value&0x0f);

}

void disptime()   //时间显示
{
 write1602_com(0x87);
 write1602_data(table1[year/10]);
 write1602_data(table1[year%10]);
 write1602_data(table1[10]);
 write1602_data(table1[months/10]);
 write1602_data(table1[months%10]);
 write1602_data(table1[10]);
 write1602_data(table1[day/10]);
 write1602_data(table1[day%10]);
 write1602_com(0xc5);
 write1602_data(table1[hour/10]);
 write1602_data(table1[hour%10]);
 write1602_data(table1[11]);
 write1602_data(table1[minute/10]);
 write1602_data(table1[minute%10]);
 write1602_data(table1[11]);
 write1602_data(table1[second/10]);
 write1602_data(table1[second%10]);
 write1602_com(0xce);
 write1602_data(table1[12]);
 write1602_data(table1[date]);
}

void inittime() //initial time setting
{
 whour=23;
 wminute=59;
 wsecond=20;
 wyear=10;
 wmonths=12;
 wdate=3;
 wday=1;
}

void main()
{
    inittime();
 init1602();
 disptop();
 dispbot();
 init1302();
 while(1)
 {
  read1302();
  disptime();
 }
}