Baud Rate Generation; Table 49. Baud Rate Deviation Error Calculation - Ck_Uart = 8 Mhz; Figure 119. Uart Clock Ck_Uart And Data Frame Timing - Holtek HT32F52220 User Manual

32-Bit Arm ® Cortex ® -M0+ MCU
HT32F52220/HT32F52230

Baud Rate Generation

The baud rate for the UART receiver and transmitter are both set with the same values. The baud-
rate divisor, BRD, has the following relationship with the UART clock which is known as CK_
UART.
Where CK_UART clock is the APB clock connected to the UART while the BRD range is from 16
to 65535.
CK_UART
Reference
Divisor Clock

Figure 119. UART Clock CK_UART and Data Frame Timing

Table 49. Baud Rate Deviation Error Calculation – CK_UART = 8 MHz
Baud rate
No
1
2
3
4
5
6
7
8
9
10
Rev. 1.10
Baud Rate Clock = CK_UART / BRD
BRD =18
Start Bit Bit0 Bit1 Bit2
Kbps Actual
2.4 2.4
9.6 9.6
19.2 19.2
57.6 57.6
115.2 115.9
230.4 228.6
460.8 470.6
921.6 888.9
2250 N/A
3000 N/A
356 of 366
Parity Bit
Bit3 Bit4 Bitn
n=6~8
CK_UART = 8 MHz
BRD Deviation Error rate
3333
833
417
139
69
35
17
9
N/A
N/A
Next Start
Stop Bit
Bit
0.01%
0.04%
-0.08%
-0.08%
0.64%
-0.79%
2.12%
-3.55%
N/A
N/A
November 09, 2018