XR16M581 Datasheet, PDF (32/51 Pages) Exar Corporation – 1.62V TO 3.63V UART WITH 16-BYTE FIFO AND VLIO INTERFACE

XR16M581
1.62V TO 3.63V UART WITH 16-BYTE FIFO AND VLIO INTERFACE
REV. 1.0.1
4.7 Modem Control Register (MCR) or General Purpose Outputs Control - Read/Write
The MCR register is used for controlling the serial/modem interface signals or general purpose inputs/outputs.
MCR[0]: DTR# Output
The DTR# pin is a modem control output. If the modem interface is not used, this output may be used as a
general purpose output.
• Logic 0 = Force DTR# output HIGH (default).
• Logic 1 = Force DTR# output LOW.
MCR[1]: RTS# Output
The RTS# pin is a modem control output and may be used for automatic hardware flow control by enabled by
EFR bit-6. If the modem interface is not used, this output may be used as a general purpose output.
• Logic 0 = Force RTS# output HIGH (default).
• Logic 1 = Force RTS# output LOW. It is required to start Auto RTS Flow Control.
MCR[2]: Reserved
OP1# is not available as an output pin on the M581. But it is available for use during Internal Loopback Mode.
In the Loopback Mode, this bit is used to write the state of the modem RI# interface signal.
MCR[3]: INT Output Enable
Enable or disable INT outputs to become active or in three-state. This bit is also used to control the OP2#
signal during internal loopback mode.
• Logic 0 = INT output disabled (three state). During internal loopback mode, OP2# is HIGH.
• Logic 1 = INT output enabled (active). During internal loopback mode, OP2# is LOW.
TABLE 11: INT OUTPUT MODES
MCR
BIT-3
INT OUTPUT
0
Three-State
1
Active
32