xr17v258 Exar Corporation, xr17v258 Datasheet - Page 47

• Manufacturer Part Number: xr17v258
• Description: 66mhz Pci Bus Octal Uart With Power Management Support
• Manufacturer: Exar Corporation

xr
REV. 1.0.0
LCR[5]: TX and RX Parity Select
If the parity bit is enabled, LCR bit [5] selects the forced parity format.
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•
•
LCR[4]: TX and RX Parity Select
If the parity bit is enabled with LCR bit [3] set to a logic 1, LCR bit [4] selects the even or odd parity format.
•
•
LCR[3]: TX and RX Parity Select
Parity or no parity can be selected via this bit. The parity bit is a simple way used in communications for data
integrity check. See
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•
LCR[2]: TX and RX Stop-bit Length Select
The length of stop bit is specified by this bit in conjunction with the programmed word length.
LCR[1:0]: TX and RX Word Length Select
These two bits specify the word length to be transmitted or received.
LCR bit [5] = logic 0, parity is not forced (default).
LCR bit [5] = logic 1 and LCR bit [4] = logic 0, parity bit is forced to a logical 1for the transmit and receive
data.
LCR bit [5] = logic 1 and LCR bit [4] = logic 1, parity bit is forced to a logical 0 for the transmit and receive
data.
Logic 0 = ODD Parity is generated by forcing an odd number of logic 1’s in the transmitted character. The
receiver must be programmed to check the same format (default).
Logic 1 = EVEN Parity is generated by forcing an even the number of logic 1’s in the transmitted character.
The receiver must be programmed to check the same format.
Logic 0 = No parity.
Logic 1 = A parity bit is generated during the transmission while the receiver checks for parity error of the
data character received.
LCR BIT [5]
Table 17
X
0
0
1
1
above for parity selection summary.
BIT [2]
BIT [1]
66MHZ PCI BUS OCTAL UART WITH POWER MANAGEMENT SUPPORT
LCR BIT [4]
0
1
1
0
0
1
1
T
X
0
1
0
1
ABLE
BIT [0]
LENGTH
5,6,7,8
17: P
W
6,7,8
0
1
0
1
ORD
5
LCR BIT [3]
ARITY
47
0
1
1
1
1
P
ROGRAMMING
S
W
TOP BIT LENGTH
(B
5 (default)
ORD LENGTH
1 (default)
IT TIME
Forced parity to space, “0”
1-1/2
Force parity to mark, “1”
6
7
8
2
P
(
ARITY SELECTION
S
Even parity
))
Odd parity
No parity
XR17V258