Transmitter interrupt request
| TRIGGER | N/A |
| NOT_FULL | N/A |
| EMPTY | N/A |
| OVERFLOW | N/A |
| UNDERFLOW | Attempt to read from an empty TX FIFO. This happens when SCB is ready to transfer data and EMPTY is ‘1’. Only used in FIFO mode. |
| BLOCKED | SW cannot get access to the EZ memory (EZ data access), due to an externally clocked EZ access. This may happen when STATUS.EC_BUSY is ‘1’. |
| UART_NACK | N/A |
| UART_DONE | N/A |
| UART_ARB_LOST | N/A |