Nations Technologies Inc.
Tel
:
+86-755-86309900
:
Address: Nations Tower, #109 Baoshen Road, Hi-tech Park North.
Nanshan District, Shenzhen, 518057, P.R.China
498
/
631
Figure 23-4 Data sampling for noise detection
Table 23-1 Data sampling for noise detection
Sampling values
NF state
Received bit value
000
0
0
001
1
0
010
1
0
011
1
1
100
1
0
101
1
1
110
1
1
111
0
1
When noise is detected in a receiving frame, you can do the following:
If three sample values are inconsistent, set the LPUART_STS.NF flag immediately.
The received data is transferred from the shift register to the buffer.
Software write 1 clears the LPUART_STS.NF flag bit.
Fractional baud rate generation
Baud rate frequency division coefficient is divided into 16-bit integer part and 8-bit decimal part. The baud rate
generator uses the value of the combination of these two parts to determine the baud rate. The fractional baud rate
divider will enable the LPUART to generate all standard baud rates.
Baud rate frequency division coefficient (LPUARTDIV) has the following relationship with system clock (PCLK) :
TX/RX baud rate =
𝑓
CLK
/ (LPUARTDIV)
Here the
𝑓
CLK
is the clock for LPUART (the clock source of LPUART can be HSI, LSE, SYSCLK, or PCLK1). The
value of LPUARTDIV is set in the baud rate configuration registers LPUART_BRCFG1 and LPUART_BRCFG2
Note: After writing LPART_BRCFG1 and LPUART_BRCFG2, the baud rate counter is replaced with the new value
Receiving
signal line
Sampling
clock
1
2
The length of a bit
3