Registers
1523
SPRUH82C – April 2013 – Revised September 2016
Copyright © 2013–2016, Texas Instruments Incorporated
Universal Asynchronous Receiver/Transmitter (UART)
Table 31-13. Line Control Register (LCR) Field Descriptions (continued)
Bit
Field
Value
Description
2
STB
Number of STOP bits generated. STB specifies 1, 1.5, or 2 STOP bits in each transmitted character.
When STB = 1, the WLS bit determines the number of STOP bits. The receiver clocks only the first
STOP bit, regardless of the number of STOP bits selected. The number of STOP bits generated is
summarized in
.
0
1 STOP bit is generated.
1
WLS bit determines the number of STOP bits:
• When WLS = 0, 1.5 STOP bits are generated.
• When WLS = 1h, 2h, or 3h, 2 STOP bits are generated.
1-0
WLS
0-3h
Word length select. Number of bits in each transmitted or received serial character. When STB = 1, the
WLS bit determines the number of STOP bits.
0
5 bits
1h
6 bits
2h
7 bits
3h
8 bits
Table 31-14. Relationship Between ST, EPS, and PEN Bits in LCR
ST Bit
EPS Bit
PEN Bit
Parity Option
x
x
0
Parity disabled: No PARITY bit is transmitted or checked
0
0
1
Odd parity selected: Odd number of logic 1s
0
1
1
Even parity selected: Even number of logic 1s
1
0
1
Stick parity selected with PARITY bit transmitted and checked as set
1
1
1
Stick parity selected with PARITY bit transmitted and checked as cleared
Table 31-15. Number of STOP Bits Generated
STB Bit
WLS Bits
Word Length Selected
with WLS Bits
Number of STOP Bits
Generated
Baud Clock (BCLK)
Cycles
0
x
Any word length
1
16
1
0h
5 bits
1.5
24
1
1h
6 bits
2
32
1
2h
7 bits
2
32
1
3h
8 bits
2
32