XR17D154 Exar Corporation, XR17D154 Datasheet - Page 38

• Manufacturer Part Number: XR17D154
• Description: Four-channel Pci-bus Uart
• Manufacturer: Exar Corporation

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PRELIMINARY
LINE CONTROL REGISTER (LCR)
The Line Control Register is used to specify the asynchronous data communication format. The word or
character length, the number of stop bits, and the parity are selected by writing the appropriate bits in this
register.
LCR[1:0]: TX and RX Word Length Select
These two bits specify the word length to be transmitted or received.
FCTR
B
IT
0
0
1
1
-7
FCTR
B
IT
0
1
0
1
-6
B
FCR
IT
X
0
0
1
1
0
0
1
1
0
0
1
1
-7
T
ABLE
B
FCR
IT
X
0
1
0
1
0
1
0
1
0
1
0
1
13: T
-6
BIT-1
RANSMIT AND
B
0
0
1
1
FCR
IT
X
0
0
0
1
1
0
0
1
1
-5
BIT
FCR
0
0
1
0
1
0
1
0
1
X
-4
BIT-0
R
0
1
0
1
ECEIVE
T
Programmable
RIGGER
via RXTRG
1 (default)
R
register
38
ECEIVE
14
16
24
28
16
56
60
4
8
8
8
FIFO T
UNIVERSAL (3.3V AND 5V) PCI BUS QUAD UART
L
EVEL
W
RIGGER
ORD LENGTH
5 (default)
via TXTRG reg-
T
Programmable
RIGGER
6
7
8
1 (default)
T
RANSMIT
ister
L
16
24
30
16
32
56
8
8
EVEL
L
EVEL
S
ELECTION
Table-A. 16C550, 16C2550,
16C2552, 16C554, 16C580
compatible.
Table-B. 16C650A compatible.
Table-C. 16C654 compatible.
Table-D. 16C850, 16c2850,
16C2852, 16C854, 16C864,
16C872 compatible.
C
OMPATIBILITY
XR17D154
REV. P1.0.0