TMS320F28379D: Ack polling in I2C bus

Hi Dhammika,

Are you using the driverLib example or the bit field (header files) I2C example within C2000ware?

Dhammika Wijesundera said:

Does F28379D's I2C module do this on its own (in hardware) if we begin a read cycle immediately after writing a byte to the EEPROM?

Are you meaning will the F2837x continuously send the slave address until it receives an ACK on it's own? If so, then no, you will have to kick off a START condition + slave address for each attempt.

Best,

Kevin

Hi Kevin,

I am using the driverLib example.

When we begin the read cycle immediately after the write cycle, don't we send the start+slave address? I cannot see that being done repeatedly.  

Hi Kevin,

I tested this by putting a break point at the line shown below. These lines are inside the ISR. The code never stops there and the read is successful.

Thanks,

Dhammika

// Interrupt source = Register Access Ready
//
// This interrupt is used to determine when the EEPROM address setup
// portion of the read data communication is complete. Since no stop bit
// is commanded, this flag tells us when the message has been sent
// instead of the SCD flag.
else if(intSource == I2C_INTSRC_REG_ACCESS_RDY)
{
    // If a NACK is received, clear the NACK bit and command a stop.
    // Otherwise, move on to the read data portion of the communication.
    if((I2C_getStatus(I2CB_BASE) & I2C_STS_NO_ACK) != 0)
    {
        I2C_sendStopCondition(I2CB_BASE);               // I set a break point here - Dhammika
        I2C_clearStatus(I2CB_BASE, I2C_STS_NO_ACK);
    }
    else if(currentMsgPtr->msgStatus == MSG_STATUS_SEND_NOSTOP_BUSY)
    {
        currentMsgPtr->msgStatus = MSG_STATUS_RESTART;
    }
}