Figure 117. Data Sampling For Noise Detection - ST STM8S Reference Manual

RM0016
When an overrun error occurs:
●
The OR bit is set.
● The RDR content will not be lost. The previous data is available when a read to
UART_DR is performed.
●
The shift register will be overwritten. The second data received during overrun is lost.
●
An interrupt is generated if the RIEN bit is set.
●
The OR bit is reset by a read to the UART_SR register followed by a UART_DR register
read operation.
Noise error
Over-sampling techniques are used for data recovery by discriminating between valid
incoming data and noise.

Figure 117. Data sampling for noise detection

RX LINE
Sample
clock
Note: The sample clock frequency is 16x baud rate.
Universal asynchronous receiver transmitter (UART)
1 2 3 4 5 6
7/16
Doc ID 14587 Rev 8
sampled values
7 8 9 10 11
One bit time
12 13 14 15 16
6/16
7/16
319/449