xr16v2651im Exar Corporation, xr16v2651im Datasheet - Page 32

• Manufacturer Part Number: xr16v2651im
• Description: High Performance Duart With 32-byte Fifo And Powersave
• Manufacturer: Exar Corporation

XR16V2651
HIGH PERFORMANCE DUART WITH 32-BYTE FIFO AND POWERSAVE FEATURE
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. Also, if 16/68# pin selects Motorola bus interface mode, this bit must be set to
logic 0.
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MCR[4]: Internal Loopback Enable
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MCR[5]: Xon-Any Enable (requires EFR bit-4=1)
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MCR[6]: Infrared Encoder/Decoder Enable (requires EFR bit-4=1)
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MCR[7]: Clock Prescaler Select (requires EFR bit-4=1)
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This register provides the status of data transfers between the UART and the host.
LSR[0]: Receive Data Ready Indicator
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LSR[1]: Receiver Overrun Error Flag
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LSR[2]: Receive Data Parity Error Tag
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4.8
Logic 0 = INT (A-B) outputs disabled (three state mode) and OP2# output set HIGH(default).
Logic 1 = INT (A-B) outputs enabled (active mode) and OP2# output set LOW.
Logic 0 = Disable loopback mode (default).
Logic 1 = Enable local loopback mode, see loopback section and
Logic 0 = Disable Xon-Any function (default).
Logic 1 = Enable Xon-Any function. In this mode, any RX character received will resume transmit operation.
The RX character will be loaded into the RX FIFO, unless the RX character is an Xon or Xoff character and
the V2651 is programmed to use the Xon/Xoff flow control.
Logic 0 = Enable the standard modem receive and transmit input/output interface (default).
Logic 1 = Enable infrared IrDA receive and transmit inputs/outputs. The TX/RX output/input are routed to the
infrared encoder/decoder. The data input and output levels conform to the IrDA infrared interface
requirement. While in this mode, the infrared TX output will be idling LOW.
PAGE 20.
Logic 0 = Divide by one. The input clock from the crystal or external clock is fed directly to the Programmable
Baud Rate Generator without further modification, i.e., divide by one (default).
Logic 1 = Divide by four. The prescaler divides the input clock from the crystal or external clock by four and
feeds it to the Programmable Baud Rate Generator, hence, data rates become one forth.
Logic 0 = No data in receive holding register or FIFO (default).
Logic 1 = Data has been received and is saved in the receive holding register or FIFO.
Logic 0 = No overrun error (default).
Logic 1 = Overrun error. A data overrun error condition occurred in the receive shift register. This happens
when additional data arrives while the FIFO is full. In this case the previous data in the receive shift register
is overwritten. Note that under this condition the data byte in the receive shift register is not transferred into
the FIFO, therefore the data in the FIFO is not corrupted by the error.
Logic 0 = No parity error (default).
Logic 1 = Parity error. The receive character in RHR does not have correct parity information and is suspect.
This error is associated with the character available for reading in RHR.
Line Status Register (LSR) - Read Only
32
Figure
12.
SEE”INFRARED MODE” ON
REV. 1.0.2