| ControlMask | A mask for the Control bits that the device supports. The device must always support the Input Buffer Empty control bit. |
| TimeOut | If applicable, the number of microseconds to wait before timing out a Read or Write operation. |
| BaudRate | If applicable, the current baud rate setting of the device; otherwise, baud rate has the value of zero to indicate that device runs at the device's designed speed. |
| ReceiveFifoDepth | The number of characters the device will buffer on input |
| DataBits | The number of characters the device will buffer on input |
| Parity | If applicable, this is the EFI_PARITY_TYPE that is computed or checked as each character is transmitted or reveived. If the device does not support parity the value is the default parity value. |
| StopBits | If applicable, the EFI_STOP_BITS_TYPE number of stop bits per character. If the device does not support stop bits the value is the default stop bit values. |