Silicon Laboratories EFR32xG14 Wireless Gecko Reference Manual page 530

18.3.2.1 Frame Format
The frame format used in asynchronous mode consists of a set of data bits in addition to bits for synchronization and optionally a parity
bit for error checking. A frame starts with one start-bit (S), where the line is driven low for one bit-period. This signals the start of a
frame, and is used for synchronization. Following the start bit are 4 to 16 data bits and an optional parity bit. Finally, a number of stop-
bits, where the line is driven high, end the frame. An example frame is shown in
page 530.
Stop or idle
S
The number of data bits in a frame is set by DATABITS in USARTn_FRAME, see
number of stop-bits is set by STOPBITS in USARTn_FRAME, see
bit should be included, and whether it should be even or odd is defined by PARITY, also in USARTn_FRAME. For communication to be
possible, all parties of an asynchronous transfer must agree on the frame format being used.
DATA BITS [3:0]
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
1100
1101
STOP BITS [1:0]
00
01
10
11
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USART - Universal Synchronous Asynchronous Receiver/Transmitter
0 3
1 2 4
Figure 18.2. USART Asynchronous Frame Format
Table 18.3. USART Data Bits
Table 18.4. USART Stop Bits
Figure 18.2 USART Asynchronous Frame Format on
Frame
[8]
[5] [6] [7]
Table 18.3 USART Data Bits on page
Table 18.4 USART Stop Bits on page
Number of Data bits
4
5
6
7
8 (Default)
9
10
11
12
13
14
15
16
Number of Stop bits
0.5
1 (Default)
1.5
2
Reference Manual
Start or idle
[P]
Stop
530, and the
530. Whether or not a parity
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