Serial Port D Transmit Buffer Empty Interrupt

Im using the Serial Port D as SPI Master in Fifo Mode.

I activated the Transmit Buffer Empty Interrupt and the Interrupt is working

but how do i reset the Interrupt pending status in the BBus Interrupt Status Register ?
the interrupt service routine is called nonestop

i thried to set the bit to 0 but its not working


This will sound counter-intuitive, but for a lot of the interrupts, you write a 1 to the interrupt to acknowledge it (as opposed to a 0).