Clock chip DS12C887 driver

/************************************************************
    Experiment name: Clock chip DS12C887 driver program
    
          Crystal oscillator: internal 8M
 Wiring method:
     1. PD port connects to DS12C887 data I/O port
     2. PA port connects to DS12C887 control port
  
 Instructions for use:
  This program can read and write DS12C887
  
**************************************************************/ 
#include
#include
#define uchar unsigned char
#define CS_H PORTA|=BIT(PA5)  
#define CS_L PORTA&=~BIT(PA5)
#define AS_H PORTA|=BIT(PA4)
#define AS_L PORTA&=~BIT(PA4)
#define R_H PORTA|=BIT(PA3)
#define W_L PORTA&=~BIT(PA3)
#define DS_H PORTA|=BIT(PA2)
#define DS_L PORTA&=~BIT(PA2)
void delay(int k) //delay
{
   int i;           
  for(i=0;i  ;
}
void init_ds12887() //initialize DS12C887
{ 
    DDRA=0xff; //control port
  DDRD=0xff; //data port
  delay(10);
  R_H ;
  delay(10);
  DS_H;
  delay(10);
  DS_L;
  delay(10);
  AS_L;
  delay(10);
  AS_H;

}
void write_ds12887(uchar addr,uchar data)//向DS12C887写入数据
{
   init_ds12887();
  PORTD=addr;
  CS_L; 
  delay(10);
  AS_L;
  delay(10);
  W_L ;
  delay(10);
  DS_H;
  PORTD=data;
  delay(10);
  DS_L;
  delay(10);
  AS_H;
  delay(10);
  CS_H;
}
uchar read_ds12887(uchar addr)//从DS12C887读出数据 
{
    uchar data;
   init_ds12887();
   CS_L;
   delay(10);
   PORTD=addr;
   AS_L;
   delay(10);
   R_H ;
   PORTD=0x00;
   DDRD=0x00;
   delay(10);
   DS_H;
   delay(10);
   data=PIND;
   return data;
   DS_L;
   delay(10);
   AS_H;
   delay(10);
   CS_H;
}