LMS=DISABLE_MODEM_LOOPBA, RTSEN=DISABLE_AUTO_RTS_FLO, CTSEN=DISABLE_AUTO_CTS_FLO
Modem Control Register. Contains controls for flow control handshaking and loopback mode.
| DTRCTRL | DTR Control. Source for modem output pin, DTR. This bit reads as 0 when modem loopback mode is active. |
| RTSCTRL | RTS Control. Source for modem output pin RTS. This bit reads as 0 when modem loopback mode is active. |
| RESERVED | Reserved, user software should not write ones to reserved bits. The value read from a reserved bit is not defined. |
| LMS | Loopback Mode Select. The modem loopback mode provides a mechanism to perform diagnostic loopback testing. Serial data from the transmitter is connected internally to serial input of the receiver. Input pin, RXD1, has no effect on loopback and output pin, TXD1 is held in marking state. The 4 modem inputs (CTS, DSR, RI and DCD) are disconnected externally. Externally, the modem outputs (RTS, DTR) are set inactive. Internally, the 4 modem outputs are connected to the 4 modem inputs. As a result of these connections, the upper 4 bits of the MSR will be driven by the lower 4 bits of the MCR rather than the 4 modem inputs in normal mode. This permits modem status interrupts to be generated in loopback mode by writing the lower 4 bits of MCR. 0 (DISABLE_MODEM_LOOPBA): Disable modem loopback mode. 1 (ENABLE_MODEM_LOOPBAC): Enable modem loopback mode. |
| RESERVED | Reserved, user software should not write ones to reserved bits. The value read from a reserved bit is not defined. |
| RTSEN | RTS enable. 0 (DISABLE_AUTO_RTS_FLO): Disable auto-rts flow control. 1 (ENABLE_AUTO_RTS_FLOW): Enable auto-rts flow control. |
| CTSEN | CTS enable. 0 (DISABLE_AUTO_CTS_FLO): Disable auto-cts flow control. 1 (ENABLE_AUTO_CTS_FLOW): Enable auto-cts flow control. |
| RESERVED | Reserved, user software should not write ones to reserved bits. The value read from a reserved bit is not defined. |