ST16C650A
2.90V TO 5.5V UART WITH 32-BYTE FIFO
áç
REV. 5.0.0
LCR[2]: TX and RX Stop-bit Length Select
The length of the stop bit is specified by this bit in conjunction with the programmed word length.
STOP BIT LENGTH
(BIT TIME(S))
WORD
LENGTH
BIT-2
0
1
1
5,6,7,8
5
1 (default)
1-1/2
2
6,7,8
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 11 for parity selection summary below.
• 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[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[5]: TX and RX Parity Select
If the parity bit is enabled, LCR BIT-5 selects the forced parity 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.
TABLE 11: PARITY SELECTION
LCR BIT-5 LCR BIT-4 LCR BIT-3
PARITY SELECTION
No parity
X
0
0
1
1
X
0
1
0
1
0
1
1
1
1
Odd parity
Even parity
Force parity to mark, “1”
Forced parity to space, “0”
LCR[6]: Transmit Break Enable
When enabled the Break control bit 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 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.
30
EXAR [ EXAR CORPORATION ]
