EEPW论坛

问 int main (void)
{
    uint8 i;
    
    uint8 data_buf[32];
    
    PINSEL0 = 0x00000000;                
    PINSEL1 = 0x00000000;
    
    IO0DIR  = BEEP;                    
    IO0SET  = BEEP;                        
    IRQEnable();                    
    I2cInit(400000);                    
    
    for (i=0; i<10; i++)
        data_buf[i] = i + '0';            
    I2C_WriteNByte(CAT24C16, X_ADD_8_SUBA, 0x00, data_buf, 10);
    DelayNS(10);     //在I2C写操作之后，
                     //为什么必须要延时，才能进行读操作？
    for (i=0; i<10; i++)
        data_buf[i] = 0;
    
    I2C_ReadNByte(CAT24C16, X_ADD_8_SUBA, 0x00, data_buf, 10);
    
    for (i=0; i<10; i++)
    {
        if (data_buf[i] != (i + '0'))
        {
            while (1)
            {                            
                IO0SET = BEEP;
                DelayNS(20);
                IO0CLR = BEEP;
                DelayNS(20);
            }
        }
    }

    IO0CLR = BEEP;                            
    DelayNS(50);
    IO0SET = BEEP;
    
    while (1);
     
    return 0;
} 答 1: 我吃饱了，一般先睡一会在上班 答 2: 要吗？不要！   我网站有IIC读写EEPROM的程序，可以从任意地址、任意长度读写 答 3: 为什么要延迟了？数据手册里写得比较清楚.

一般的EEPROM，每发送完写指令和写数据时，
必须要有一个5-10ms的延迟.

否则数据写不进，
不信你可以试一下. 答 4: 谢谢哦！ 答 5: 对于串行EEPROM的写操作,建议采用ACKNOWLEDGE POLLING代替延时ACKNOWLEDGE POLLING: Once the internally-timed write cycle has started and the EEPROM inputs are disabled, acknowledge polling CAN be initiated. This involves sending a start condition followed by the device address word. The Read/Write bit is representative of the operation desired. Only if the internal write cycle has completed will the EEPROM respond with a “0”, allowing the read or write sequence to continue. 答 6: 简单地说就是在串行EEPROM开始内部写操作过程到完成这段时间，不管你试图进行读或者写操作，芯片都不会响应。

这样一来你就可以不断地尝试向该器件发出start condition，当它以“0”来应答时，则表明它的上一个写过程已经完成，你可以接着进行下一步的操作了。

延时是一种相对简单的方法，个人认为ACKNOWLEDGE POLLING更省时，适应性更强。 答 7: john_light说得很正确.