XR17L154CV EXAR [Exar Corporation], XR17L154CV Datasheet - Page 37

• Manufacturer Part Number: XR17L154CV
• Description: 3.3V PCI BUS QUAD UART
• Manufacturer: EXAR [Exar Corporation]

XR17L154
3.3V PCI BUS QUAD UART
REV. 1.1.0
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[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
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. 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).
LCR[5]: TX and RX Parity Select
If the parity bit is enabled, LCR BIT-5 selects the forced parity format.
LCR[6]: Transmit Break Enable
When enabled the Break control bit it 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 parity.
Logic 1 = A parity bit is generated during the transmission while the receiver checks for parity error of the
data character received.
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.
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 1 for 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 = 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.
Table 14
LCR B
for parity selection summary below.
X
0
0
1
1
IT
BIT-2
-5 LCR B
0
1
1
X
T
0
1
0
1
ABLE
W
IT
ORD LENGTH
-4 LCR B
5,6,7,8
6,7,8
14: P
5
0
1
1
1
1
ARITY SELECTION
IT
37
-3
Forced parity to space, “0”
Force parity to mark, “1”
S
TOP BIT LENGTH
P
(B
1 (default)
ARITY SELECTION
IT TIME
Even parity
Odd parity
1-1/2
No parity
2
(
S
))
DISCONTINUED
áç
áç
áç
áç