XR21V1414 Datasheet, PDF (20/26 Pages) Exar Corporation – 4-CH FULL-SPEED USB UART

XR21V1414
4-CH FULL-SPEED USB UART
REV. 1.0.0
3.3.5 CHARACTER_FORMAT Register Description (Read/Write)
This register controls the character format such as the word length (7, 8 or 9), parity (odd, even, forced ’0’, or
forced ’1’) and number of stop bits (1 or 2).
CHARACTER_FORMAT[3:0]: Data Bits.
TABLE 9: DATA BITS
DATA BITS
CHARACTER_FORMAT[3:0]
7
0111
8
1000
9
1001
All other values for CHARACTER_FORMAT[3:0] are reserved.
CHARACTER_FORMAT[6:4]: Parity Mode Select
These bits select the parity mode. If 9-bit data mode has been selected, then writing to these bits will not have
any effect. In other words, there will not be an additional parity bit.
TABLE 10: PARITY SELECTION
BIT-6
BIT-5
BIT-4
PARITY SELECTION
0
0
0
No parity
0
0
1
Odd parity
0
1
0
Even parity
0
1
1
Force parity to mark, “1”
1
0
0
Force parity to space, “0”
CHARACTER_FORMAT[7]: Stop Bit select
This register selects the number of stop bits to add to the transmitted character and how many stop bits to
check for in the received character.
TABLE 11: STOP BIT SELECTION
BIT-7
NUMBER OF STOP BITS
0
1 stop bit
1
2 stop bits
3.3.6 FLOW_CONTROL Register Description (Read/Write)
These registers select the flow control mode. These registers should only be written to when the UART is
disabled. Writing to the FLOW_CONTROL register when the UART is enabled will result in undefined
behavior.
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