I2C调试时SCL波形异常

Question

我用的国民技术031芯片调试I2C功能，发现SCL和SDA的波形如图所示，在第9，第18第27的位置均为ACK信号，但是27应答信号之后的SCL就连续出现两个高电平，不知道是哪里出了问题，哪位小伙伴能帮忙看看！

以下是初始化
```c
int i2c_master_init(void)
{
    I2C_InitType i2c1_master;
    GPIO_InitType i2c1_gpio;
    RCC_EnableAPB1PeriphClk(RCC_APB1_PERIPH_I2C1, ENABLE);
    RCC_EnableAPB2PeriphClk(RCC_APB2_PERIPH_GPIOB, ENABLE);

    GPIO_InitStruct(&i2c1_gpio);
    /*PB6 -- SCL; PB7 -- SDA*/
    i2c1_gpio.Pin        = I2Cx_SCL_PIN | I2Cx_SDA_PIN;
    i2c1_gpio.GPIO_Speed = GPIO_SPEED_HIGH; 
    i2c1_gpio.GPIO_Mode  = GPIO_MODE_AF_OD;
    i2c1_gpio.GPIO_Alternate = GPIO_AF_I2C;
    i2c1_gpio.GPIO_Pull = GPIO_PULL_UP; 
    GPIO_InitPeripheral(GPIOx, &i2c1_gpio);

    I2C_DeInit(I2Cx);
    i2c1_master.BusMode     = I2C_BUSMODE_I2C;
    i2c1_master.FmDutyCycle = I2C_FMDUTYCYCLE_2; //if the spped greater than 400KHz, the FmDutyCycle mast be configured to I2C_FMDUTYCYCLE_2
    i2c1_master.OwnAddr1    = I2C_MASTER_ADDR;
    i2c1_master.AckEnable   = I2C_ACKEN;
    i2c1_master.AddrMode    = I2C_ADDR_MODE_7BIT;
    i2c1_master.ClkSpeed    = 100000;

    I2C_Init(I2Cx, &i2c1_master);

    I2C_Enable(I2Cx, ENABLE);
    return 0;
}

以下是在main函数中的while循环里调用的函数

```c
 I2C_EE_WriteBuffer(tx_buf, TEST_EEPROM_ADDR, 1);//TEST_EEPROM_SIZE
void I2C_EE_WriteBuffer(u8* pBuffer, u16 WriteAddr, u16 NumByteToWrite)
{
    if (I2C_GetFlag(I2Cx, I2C_FLAG_BUSY))
    {
        return;
    }
    I2C_pBuffer        = pBuffer;
    I2C_WriteAddr      = WriteAddr;
    I2C_NumByteToWrite = NumByteToWrite;

    while (I2C_NumByteToWrite > 0)
    {
        I2C_EE_WriteOnePage(I2C_pBuffer, I2C_WriteAddr, I2C_NumByteToWrite);
    }
}

void I2C_EE_WriteOnePage(u8* pBuffer, u16 WriteAddr, u16 NumByteToWrite)
{
    u8 NumOfPage = 0, NumOfSingle = 0, Addr = 0, count = 0;

    Addr        = WriteAddr % I2C_PageSize;
    count       = I2C_PageSize - Addr;
    NumOfPage   = NumByteToWrite / I2C_PageSize;
    NumOfSingle = NumByteToWrite % I2C_PageSize;

    I2C_NumByteWritingNow = 0;
    /** If WriteAddr is I2C_PageSize aligned */
    if (Addr == 0)
    {
        /** If NumByteToWrite < I2C_PageSize */
        if (NumOfPage == 0)
        {
            I2C_NumByteWritingNow = NumOfSingle;
            I2C_EE_PageWrite(pBuffer, WriteAddr, NumOfSingle);
        }
        /** If NumByteToWrite > I2C_PageSize */
        else
        {
            I2C_NumByteWritingNow = I2C_PageSize;
            I2C_EE_PageWrite(pBuffer, WriteAddr, I2C_PageSize);
        }
    }
    /** If WriteAddr is not I2C_PageSize aligned */
    else
    {
        /* If NumByteToWrite < I2C_PageSize */
        if (NumOfPage == 0)
        {
            I2C_NumByteWritingNow = NumOfSingle;
            I2C_EE_PageWrite(pBuffer, WriteAddr, NumOfSingle);
        }
        /* If NumByteToWrite > I2C_PageSize */
        else
        {
            if (count != 0)
            {
                I2C_NumByteWritingNow = count;
                I2C_EE_PageWrite(pBuffer, WriteAddr, count);
            }
        }
    }
}

void I2C_EE_PageWrite(u8* pBuffer, u16 WriteAddr, u16 NumByteToWrite)
{
#if PROCESS_MODE == 0 /* polling */
    sEETimeout = sEE_LONG_TIMEOUT;
    while (I2C_GetFlag(I2Cx, I2C_FLAG_BUSY))
    {
        if ((sEETimeout--) == 0)
            sEE_TIMEOUT_UserCallback();
    }
    /** Send START condition */
    I2C_GenerateStart(I2Cx, ENABLE);
    /** Test on EV5 and clear it */
    sEETimeout = sEE_LONG_TIMEOUT;
    while (!I2C_CheckEvent(I2Cx, I2C_EVT_MASTER_MODE_FLAG))
    {
        if ((sEETimeout--) == 0)
            sEE_TIMEOUT_UserCallback();
    }
    /** Send EEPROM address for write */
    I2C_SendAddr7bit(I2Cx, EEPROM_ADDRESS, I2C_DIRECTION_SEND);
    /** Test on EV6 and clear it */
    sEETimeout = sEE_LONG_TIMEOUT;
    while (!I2C_CheckEvent(I2Cx, I2C_EVT_MASTER_TXMODE_FLAG))
    {
        if ((sEETimeout--) == 0)
            sEE_TIMEOUT_UserCallback();
    }
    /** Send the EEPROM's internal address to write to */
    I2C_SendData(I2Cx, WriteAddr);
    /** Test on EV8 and clear it */
    sEETimeout = sEE_LONG_TIMEOUT;
    while (!I2C_CheckEvent(I2Cx, I2C_EVT_MASTER_DATA_SENDED))
    {
        if ((sEETimeout--) == 0)
            sEE_TIMEOUT_UserCallback();
    }
    /** While there is data to be written */
    while (NumByteToWrite--)
    {
        /** Send the current byte */
        I2C_SendData(I2Cx, *pBuffer);
        /** Point to the next byte to be written */
        pBuffer++;
        /** Test on EV8 and clear it */
        sEETimeout = sEE_LONG_TIMEOUT;
        while (!I2C_CheckEvent(I2Cx, I2C_EVT_MASTER_DATA_SENDED))
        {
            if ((sEETimeout--) == 0)
                sEE_TIMEOUT_UserCallback();
        }
    }
    /** Send STOP condition */
    I2C_GenerateStop(I2Cx, ENABLE);
    I2C_EE_WaitEepromStandbyState();
    I2C_EE_WriteOnePageCompleted();

#endif
}

Answer 1

1、主要查看程序，如果使用的是模拟IIC，看看for循环，还有应答部分的程序
2、最好使用逻辑分析仪，看看SDA数据是否正确
3、把程序段贴出来