RS-232 Baud Rate Change cont’d.
Baud Change; Parity, word length, stop bits.
Byte 5 (UB3)
UB3 sets the LCR register on the UART
Table 14. Byte 5 (UB3)
Bit 7 | Bit 6 | Bit 5 | Bit 4 | Bit 3 | Bit 2 | Bit 1 | Bit 0 |
Divisor | Set | Set | Even | Parity | Stop | Word | Word |
latch | break | parity | parity | enable | bits | length 1 | length 0 |
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Bit 7 = 1 allows baud rate divisor to be changed. 0 baud rate change is blocked.
Bit seven should not be set. The setting and resetting of this bit is handled internally.
Bit 6 = 1 forces the transmitter output to a logic 0 for alerting the remote receiver to a line break.
0 No break condition.
Bits 5, 4, 3 work together to set parity.
Table 15. Parity Setup
Bit 5 | Bit 4 | Bit 3 | Parity Selection |
X | X | 0 | No parity * |
0 | 0 | 1 | Odd parity |
0 | 1 | 1 | Even parity |
1 | 0 | 1 | Force parity “1” |
1 | 1 | 1 | Force parity “0” |
* Setup Default Value.
1939STB4600 Manual | 11 |
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