XR16C872CQ EXAR [Exar Corporation], XR16C872CQ Datasheet - Page 21

• Manufacturer Part Number: XR16C872CQ
• Description: DUAL UART WITH 1284 PARALLEL PORT AND PLUG-AND-PLAY CONTROLLER
• Manufacturer: EXAR [Exar Corporation]

Note *3: The value represents the register’s initialized HEX value. An “X” signifies a 4-bit un-initialized nibble.
UART INTERNAL REGISTERS (continue)
Rev. 1.00
Enhanced Registers are accessible only when LCR is set to 0xBF.
EMSR Register is accessible only when FCTR bit 6 is set to logic 1.
A2 A1 A0
0
0
0
1
1
1
1
1
0
0
1
0
0
1
1
1
0
0
0
1
0
1
1
1
EMSR [00]
Xoff-1[00]
Xoff-2[00]
Xon-1[00]
Xon-2[00]
TRG [00]
FCTR [00]
[Default]
EFR [00]
Register
Note *3
bit-15
bit-15
Rx/Tx
Mode
BIT-7
Trig/
Auto
bit-7
bit-7
Used
CTS
Not
FC
SPR/EMSR
Select
bit-14
bit-14
BIT-6
Trig/
Auto
bit-6
bit-6
Used
RTS
Not
FC
DISCONTINUED
Hysteresis Hysteresis
Special
bit-13
bit-13
select
Trig/
Char.
BIT-5
bit-5
bit-5
bit-3
bit-1
RTS
Trig
FC
21
1 2 3 4 5 6 7 8
1 2 3 4 5 6 7 8
1 2 3 4 5 6 7 8
1 2 3 4 5 6 7 8
1 2 3 4 5 6 7 8
1 2 3 4 5 6 7 8
1 2 3 4 5 6 7 8
1 2 3 4 5 6 7 8
1 2 3 4 5 6 7 8
1 2 3 4 5 6 7 8
1 2 3 4 5 6 7 8
1 2 3 4 5 6 7 8
1 2 3 4 5 6 7 8
ISR, FCR
bits 4-5,
Enable
IER bits
bits 5-7
bit-12
bit-12
Trig/
BIT-4
bit-4
bit-4
bit-2
MCR
bit-0
RTS
Trig
FC
4-7,
Reserved Reserved
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Control
control
Cont-3
RS485
bit-11
bit-11
Tx,Rx
BIT-3
Auto
bit-3
bit-3
Trig
FC
Control
Cont-2
bit-10
bit-10
Tx,Rx
Trig/
BIT-2
bit-2
bit-2
IrRx
Inv.
FC
XR16C872
Hysteresis Hysteresis
Control
Cont-1
Count
Tx,Rx
Rx/Tx
Trig/
FIFO
BIT-1
bit-1
bit-9
bit-1
bit-9
ALT.
bit-1
RTS
FC
Cont-0
Control
Count
Rx/Tx
Tx,Rx
Trig/
bit-0
bit-8
bit-0
bit-8
FIFO
BIT-0
bit-0
RTS
FC