[参考译文] TMS320F28069：C2000 I2C ISR 未更新中断源

Uint8 i2cdrvCmdCheckSlavePresent(
        Uint8 slaveAddr,
        Uint32 timeoutMs)
{
    Uint8 isSuccess = !i2cdrvIsBusy();
    if (isSuccess)
    {
        m_state = I2CDRVSTATE_BUSY;
        ...

        I2caRegs.I2CSAR = slaveAddr;
        // Enable ARDY and NACK interrupts
        I2caRegs.I2CIER.all = 0x0006;
        // Mode -> FREE, STT, MST, TRX, RM, IRS all set.
        I2caRegs.I2CMDR.all = 0x66A0;
    }

    return isSuccess;
}

static void _init(void)
{
    // Put in reset
    I2caRegs.I2CMDR.all = 0x0000;

    // Add our interrupt handler to vector table
    EALLOW;
    PieVectTable.I2CINT1A = &_i2cInt1AISR;
    EDIS;
    // Enable I2C interrupts in the PIE: Group 8 interrupt 1 and 2
    PieCtrlRegs.PIEIER8.bit.INTx1 = 1;
    //PieCtrlRegs.PIEIER8.bit.INTx2 = 1;
    // Enable CPU INT8 which is connected to PIE group 8
    IER |= M_INT8;

    // Set our own address
    I2caRegs.I2COAR = 0x0001;

    // Clocks
    I2caRegs.I2CPSC.all = CLK_PRESCALE;
    I2caRegs.I2CCLKL = CLK_LOW;
    I2caRegs.I2CCLKH = CLK_HIGH;

    // Disable all ints
    I2caRegs.I2CIER.all = 0x0000;

    // Take out of reset
    I2caRegs.I2CMDR.bit.IRS = 1;
}

// I2C-1A Interrupt - handles the basic I2C
static interrupt void _i2cInt1AISR(void)
{
    // Read interrupt source
     Uint16 intSrc = I2caRegs.I2CISRC.all; //this is always returning 0. it should return I2C_NACK_ISRC or I2C_ARDY_ISRC

    switch(intSrc)
    { .... }
}