Interrupt Mask Register
| RXRDY | RXRDY Interrupt Mask |
| TXRDY | TXRDY Interrupt Mask |
| ENDRX | End of Receive Buffer Interrupt Mask |
| ENDTX | End of Transmit Buffer Interrupt Mask |
| OVRE | Overrun Error Interrupt Mask |
| TXEMPTY | TXEMPTY Interrupt Mask |
| UNRE | SPI Underrun Error Interrupt Mask |
| TXBUFE | Transmit Buffer Empty Interrupt Mask |
| RXBUFF | Receive Buffer Full Interrupt Mask |