interrupt enable register
| SLAVE_TRAN_COMP_INT_ENA | enable slave transit complete interrupt |
| ARBITRATION_LOST_INT_ENA | enable arbitration lost interrupt |
| MASTER_TRAN_COMP_INT_ENA | enable master transit complete interrupt |
| TRANS_COMPLETE_INT_ENA | enable transit complete interrupt |
| TIME_OUT_INT_ENA | enable time out interrupt |
| ACK_ERR_INT_ENA | enable eack error interrupt |
| RX_DATA_INT_ENA | enable receive data interrupt |
| TX_DATA_INT_ENA | enable transit data interrupt |
| DETECT_START_INT_ENA | enable detect start interrupt |