使用mc9s12dg128的iic接口调试at24c01a，一个iic接口的eeprom

老是调不通，程序老死机。大家给看看是什么问题。。

#pragma LINK_INFO DERIVATIVE "mc9s12dg128b"

void IIC_int()
{
  IBFD=0xfc;
  IBAD=0xee;
  IBCR|=0x80;
}

void IIC_Start()
{
  IBCR|=0x30;
}

void IIC_Stop()
{
  IBCR&=0xdf;    //stop
}

void uart_init(void)
{
  SCI1CR2=0x08;
  SCI1BDH=0x00;
  SCI1BDL=0x9C;
}

void uart_putchar(unsigned char ch)
{
 while(!(SCI1SR1&0x40))
  {}         
  SCI1DRL=ch;
} 

uchar send_data(uchar ch)
{
  IBSR_IBIF=1;      //clear flag
  IBDR=ch;
  //while(!IBSR_IBB); //if the bus is busy
  while(!IBSR_IBIF);//wait for acknowledge
}

void wait_ack()
{
  while(IBSR_RXAK); //
}

void main(void) {
  /* put your own code here */
  EnableInterrupts;
  uart_init();
  IIC_int();
  while(IBSR_IBB);
  IIC_Start();
//write
  send_data(0xa0);
  wait_ack();
  send_data(0x02);
  wait_ack();
  send_data(0x78);
  wait_ack();
  IIC_Stop();    //stop
//read
  //IIC_int();
  IIC_Start();
  send_data(0xa0);
  wait_ack();
 
 
  send_data(0x02);
  wait_ack();
 
  IIC_Start();
  send_data(0xa1);
  wait_ack();
  //while(!IBSR_RXAK); //
  IBCR&=0xef;       //receive
  IBSR_IBIF=1;      //clear flag
  //uart_putchar(IBSR);
  while(!IBSR_IBIF);
  //uart_putchar(0xf0);
  //IBDR=0xff;
  uart_putchar(IBDR);
  IIC_Stop();    //stop
  IBSR_IBIF=1;      //clear flag
  for(;;) {} /* wait forever */
}