我再程序里先写满1片24C02,再把里面的内容读到片内RAM中.

虽然能正确写进去了,但是读的时候总是读出256个0xFF

请大家帮忙看看什么问题 !!!!!!! 

/***********************************************************/
void I2C0_init(void) {
  unsigned char i;
  re_send_sladd=0;//it's used in the begin of the read to send the slave address again acording the I2C protocol
  i2c_step=0;//use this semaphore to control the cycle of read and write
  new_inner_page=1;//1 means a new page is begin,0 means the old page is not finished
  i2c_page_counter=0;//24c02 has 32 pages with 8 byte per page
  byte_write_conter=0;
 
  I2C_frequency_define=0xBF;//use the lowest clock in debug
  I2C_control_address_length=0;//use 7bit addressing
  I2C_start;
  i=I2C_data;//dummy read from IBDR register
}
/***********************************************************/
void I2C0_start(unsigned char mode_select,unsigned char add_24c02,unsigned char direc_control){
  while((I2C_status&0x20)>>5==1);//wait for the bus idle
  I2C_control|=(0x41|mode_select);//interrupt enable,master,transmit,acknowledge if need  
  I2C_data=add_24c02|direc_control;//slave address and write to slave
  while((I2C_status&0x20)>>5!=1);//ensure the bus is engrossed by it 
}
/***********************************************************/
void main(void) {
  SetupXGATE();
  I2C0_init();
  interrupt_init();
  EnableInterrupts;

  for(;;) {
    switch(i2c_step) {
      case 0:
        i2c_step=1;
        I2C0_start(master_write,i2c_chip_add,write);//generate START,send slave address;master write
        break;
      case 1:
        break;
      case 2:
        i2c_step=1;
        if(re_send_sladd==0){ //the first time to send 24C02's address
          re_send_sladd=1;//make the following ISR switch to "case master_r_select_add"
          I2C0_start(master_write,i2c_chip_add,write); 
        }
        else if(re_send_sladd==2){
          re_send_sladd=0;
          I2C_control&=0xEF;//clear the Tx/Rx bit to select receive mode
          Repeat_start;//generate repeat start
          I2C_data=i2c_chip_add|read;
        }
        else{;}
        break;
      default:{;}
    }//end of switch
  }//end of the loop
}//end of main