XR16L2750 Datasheet, PDF (28/49 Pages) Exar Corporation – 2.25V TO 5.5V DUART WITH 64-BYTE FIFO

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XR16L2750
2.25V TO 5.5V DUART WITH 64-BYTE FIFO
REV. 1.0.0
TABLE 11: PARITY SELECTION
LCR BIT-5 LCR BIT-4 LCR BIT-3 PARITY SELECTION
X
X
0
No parity
0
0
1
Odd parity
0
1
1
Even parity
1
0
1
Force parity to mark,
“1”
1
1
1
Forced parity to
space, “0”
LCR[6]: Transmit Break Enable
When enabled, the Break control bit causes a break condition to be transmitted (the TX output is forced to a
“space’, logic 0, state). This condition remains, until disabled by setting LCR bit-6 to a logic 0.
• Logic 0 = No TX break condition. (default)
• Logic 1 = Forces the transmitter output (TX) to a “space”, logic 0, for alerting the remote receiver of a line
break condition.
LCR[7]: Baud Rate Divisors Enable
Baud rate generator divisor (DLL/DLM) enable.
• Logic 0 = Data registers are selected. (default)
• Logic 1 = Divisor latch registers are selected.
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 to a logic 1 (default).
• Logic 1 = Force DTR# output to a logic 0.
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 to a logic 1 (default).
• Logic 1 = Force RTS# output to a logic 0.
MCR[2]: Reserved
OP1# is not available as an output pin on the 2750. 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]: OP2# Output / INT Output Enable
This bit enables or disables the operation of INT, interrupt output. If INT output is not used, OP2# can be used
as a general purpose output.
• Logic 0 = INT (A-B) outputs disabled (three state mode) and OP2# output set to a logic 1 (default).
• Logic 1 = INT (A-B) outputs enabled (active mode) and OP2# output set to a logic 0.
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