24XX读写程序，方便同志们数量掌握24系列的读写规律

/*---------------- 24CXX读写程序 ----------------*/
void start24c(void)            //开始启动
{ sda=1;scl=1;
   nop();
   sda=0;
   nop();
} 
void stop24c(void)             //停止
{ sda=0;scl=1;
   nop();
   sda=1;
   nop();
}
void ack24c(void)              //正向回应
{ sda=0;
   nop();
   scl=1;
   nop();
   scl=0;
}
void noack24c(void)            //反向回应
{ sda=1;
   nop();
   scl=1;
   nop();
   scl=0;
}
void send24c(uchar dd)         //内部函数,发送数到i2c
{ uchar bitcounter=8;
   uchar temp;

   do {
       temp=dd;
       scl=0;
       nop();
       if((temp&0x80)==0x80)
         sda=1;
       else
         sda=0;
       scl=1;
       temp=dd<<1;
       dd=temp;
       bitcounter--;
       } while(bitcounter);
    scl=0;
}
uchar rece24c(void)                      //内部函数,从i2c接收数
{  uchar temp=0,temp1=0,bitcounter=8;
    sda=1;
    do {
       scl=0;
       nop();
       scl=1;
       nop();
       if(sda)
         temp=temp|0x01;
       else
         temp=temp&0xfe;
       if(bitcounter-1)
         { temp1=temp<<1;
           temp=temp1;