GD32F103的IIC模块在进行eeprom读取的时候，当读取的字节数为2时，需要将I2C_CTL0的POAP置为1；POAP的定义如下：
       0：ACKEN位决定对当前正在接收的字节发送ACK;
       1: ACKEN位决定是否对下一个字节发送ACK.
我的理解时：当读取的字节数为2时，该位置1，表示接收第一个字节后，发送ACK;接收第二个字节后，不发送ACK。这样就能保证时序的正确性。
不知道各位大佬是如何理解的，请赐教。谢谢！

代码如下：
void eeprom_buffer_read(uint8_t* p_buffer, uint8_t read_address, uint16_t number_of_byte)
{  
    /* wait until I2C bus is idle */
    while(i2c_flag_get(I2C0, I2C_FLAG_I2CBSY));

    if(2 == number_of_byte)
   {
        i2c_ackpos_config(I2C0,I2C_ACKPOS_NEXT);   //如果接收的的字节数等于2，则将将I2C_CTL0的POAP置为1。
    }

    /* send a start condition to I2C bus */
    i2c_start_on_bus(I2C0);

    /* wait until SBSEND bit is set */
    while(!i2c_flag_get(I2C0, I2C_FLAG_SBSEND));

    /* send slave address to I2C bus */
    i2c_master_addressing(I2C0, eeprom_address, I2C_TRANSMITTER);

    /* wait until ADDSEND bit is set */
    while(!i2c_flag_get(I2C0, I2C_FLAG_ADDSEND));

    /* clear the ADDSEND bit */
    i2c_flag_clear(I2C0,I2C_FLAG_ADDSEND);

    /* wait until the transmit data buffer is empty */
    while(SET != i2c_flag_get( I2C0 , I2C_FLAG_TBE));

    /* enable I2C0*/
    i2c_enable(I2C0);

    /* send the EEPROM's internal address to write to */
    i2c_data_transmit(I2C0, read_address);  

    /* wait until BTC bit is set */
    while(!i2c_flag_get(I2C0, I2C_FLAG_BTC));

    /* send a start condition to I2C bus */
    i2c_start_on_bus(I2C0);

    /* wait until SBSEND bit is set */
    while(!i2c_flag_get(I2C0, I2C_FLAG_SBSEND));

    /* send slave address to I2C bus */
    i2c_master_addressing(I2C0, eeprom_address, I2C_RECEIVER);

    if(number_of_byte < 3){
        /* disable acknowledge */
        i2c_ack_config(I2C0,I2C_ACK_DISABLE);
    }

    /* wait until ADDSEND bit is set */
    while(!i2c_flag_get(I2C0, I2C_FLAG_ADDSEND));

    /* clear the ADDSEND bit */
    i2c_flag_clear(I2C0,I2C_FLAG_ADDSEND);

    if(1 == number_of_byte){
        /* send a stop condition to I2C bus */
        i2c_stop_on_bus(I2C0);
    }

    /* while there is data to be read */
    while(number_of_byte){
        if(3 == number_of_byte){
            /* wait until BTC bit is set */
            while(!i2c_flag_get(I2C0, I2C_FLAG_BTC));

            /* disable acknowledge */
            i2c_ack_config(I2C0,I2C_ACK_DISABLE);
        }
        if(2 == number_of_byte){
            /* wait until BTC bit is set */
            while(!i2c_flag_get(I2C0, I2C_FLAG_BTC));

            /* send a stop condition to I2C bus */
            i2c_stop_on_bus(I2C0);
        }

        /* wait until the RBNE bit is set and clear it */
        if(i2c_flag_get(I2C0, I2C_FLAG_RBNE)){
            /* read a byte from the EEPROM */
            *p_buffer = i2c_data_receive(I2C0);

            /* point to the next location where the byte read will be saved */
            p_buffer++;

            /* decrement the read bytes counter */
            number_of_byte--;
        }
    }

    /* wait until the stop condition is finished */
    while(I2C_CTL0(I2C0)&0x0200);

    /* enable acknowledge */
    i2c_ack_config(I2C0,I2C_ACK_ENABLE);

    i2c_ackpos_config(I2C0,I2C_ACKPOS_CURRENT);
}