TMS320F280049C: I2C: missing Tx FIFO interrupt

Hi,

I have a problem in getting the Tx FIFO interrupt to work properly.

During init I initialize the TX FIFO level bits, write a one bit to the TXFFINTCLR bit (bit 6) in the I2CFFTX  register in order to clear the TXFFINT, but does not enable the TX FIFO interrupt.

After init I have I2CFFTX (reg 0x20) = 0x6082

Then I try to send one byte by putting the byte in the  I2C Data Transmit Register,  write a one bit to the TXFFINTCLR bit (bit 6) in the I2CFFTX  register in order to clear the TXFFINT and

finally enables the TX FIFO interrupt.

After the 'byte-send', the I2CFFTX =  0x61a2, but I don't get an interrupt. Why ?

However when I 'manually' clear the TXFFINT (by writing a one bit to the TXFFINTCLR bit (bit 6) in the I2CFFTX  register) the interrupt comes! - Why ?

Regards

Martin Rohde