TABLE 16: PARITY PROGRAMMING
BIT [5]
BIT [4]
BIT [3]
PARITY SELECTION
X
0
No parity
0
1
Odd parity
0
1
Even parity
1
0
1
Force parity to mark, “1”
1
Forced parity to space, “0”
XR17V352
50
HIGH PERFORMANCE DUAL PCI EXPRESS UART
REV. 1.0.3
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).
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[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 Table 16 above for parity selection summary.
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[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.
WORD
LENGTH
STOP BIT LENGTH
(BIT TIME(S))
0
5,6,7,8
1 (default)
1
5
1-1/2
1
6,7,8
2
LCR[1:0]: TX and RX Word Length Select
These two bits specify the word length to be transmitted or received.
WORD LENGTH
0
5 (default)
0
1
6
1
0
7
1
8
4.8
Modem Control Register (MCR) - Read/Write
The MCR register is used for controlling the modem interface signals or general purpose inputs/outputs.
LCR
BIT [2]
BIT [1]
BIT [0]