TERI=NO_STATE_CHANGE, DELTADCD=NO_STATE_CHANGE, DELTADSR=NO_STATE_CHANGE, DELTACTS=NO_STATE_CHANGE
Modem status register
| DELTACTS | Set upon state change of input CTS. Cleared on a MSR read. 0 (NO_STATE_CHANGE): No change detected on modem input CTS. 1 (STATE_CHANGE_DETECTE): State change detected on modem input CTS. |
| DELTADSR | Set upon state change of input DSR. Cleared on a MSR read. 0 (NO_STATE_CHANGE): No change detected on modem input DSR. 1 (STATE_CHANGE_DETECTE): State change detected on modem input DSR. |
| TERI | Trailing Edge RI. Set upon low to high transition of input RI. Cleared on a MSR read. 0 (NO_STATE_CHANGE): No change detected on modem input, RI. 1 (LOW_TO_HIGH_TRANSITI): Low-to-high transition detected on RI. |
| DELTADCD | Set upon state change of input DCD. Cleared on a MSR read. 0 (NO_STATE_CHANGE): No change detected on modem input DCD. 1 (STATE_CHANGE_DETECTE): State change detected on modem input DCD. |
| CTS | Clear To Send State. Complement of input signal CTS. This bit is connected to MCR[1] in modem loopback mode. |
| DSR | Data Set Ready State. Complement of input signal DSR. This bit is connected to MCR[0] in modem loopback mode. |
| RI | Ring Indicator State. Complement of input RI. This bit is connected to MCR[2] in modem loopback mode. |
| DCD | Data Carrier Detect State. Complement of input DCD. This bit is connected to MCR[3] in modem loopback mode. |
| RESERVED | Reserved |