ST STM32F446 Series User Manual

Universal synchronous asynchronous receiver transmitter (USART) RM0390
812/1328 RM0390 Rev 4
Table 150. Error calculation for programmed baud rates at f
PCLK
= 16 MHz or f
PCLK
= 24 MHz,
oversampling by 8
(1)
Oversampling by 8 (OVER8=1)
Baud rate f
PCLK
= 16 MHz f
PCLK
= 24 MHz
S.No Desired Actual
Value
programmed
in the baud
rate register
% Error =
(Calculated -
Desired) B.rate /
Desired B.rate
Actual
Value
programmed
in the baud
rate register
% Error
1 1.2 KBps 1.2 KBps 1666.625 0 1.2 KBps 2500 0
2 2.4 KBps 2.4 KBps 833.375 0 2.4 KBps 1250 0
3 9.6 KBps 9.598 KBps 208.375 0.02 9.6 KBps 312.5 0
4 19.2 KBps 19.208 KBps 104.125 0.04 19.2 KBps 156.25 0
5 38.4 KBps 38.369 KBps 52.125 0.08 38.4 KBps 78.125 0
6 57.6 KBps 57.554 KBps 34.75 0.08 57.554 KBps 52.125 0.08
7 115.2 KBps 115.108 KBps 17.375 0.08 115.385 KBps 26 0.16
8 230.4 KBps 231.884 KBps 8.625 0.64 230.769 KBps 13 0.16
9 460.8 KBps 457.143 KBps 4.375 0.79 461.538 KBps 6.5 0.16
10 921.6 KBps 941.176 KBps 2.125 2.12 923.077 KBps 3.25 0.16
11 2 MBps 2000 KBps 1 0 2000 KBps 1.5 0
12 3 MBps NA NA NA 3000 KBps 1 0
1. The lower the CPU clock the lower the accuracy for a particular baud rate. The upper limit of the achievable baud rate can
be fixed with these data.
Table 151. Error calculation for programmed baud rates at f
PCLK
= 8 MHz or f
PCLK
= 16 MHz,
oversampling by 16
(1)
Oversampling by 16 (OVER8=0)
Baud rate f
PCLK
= 8 MHz f
PCLK
= 16 MHz
S.No Desired Actual
Value
programmed
in the baud
rate register
% Error =
(Calculated -
Desired)B.Rate
/Desired B.Rate
Actual
Value
programmed
in the baud
rate register
% Error
1 2.4 KBps 2.400 KBps 208.3125 0.00% 2.400 KBps 416.6875 0.00%
2 9.6 KBps 9.604 KBps 52.0625 0.04% 9.598 KBps 104.1875 0.02%
3 19.2 KBps 19.185 KBps 26.0625 0.08% 19.208 KBps 52.0625 0.04%
4 57.6 KBps 57.554 KBps 8.6875 0.08% 57.554 KBps 17.3750 0.08%
5 115.2 KBps 115.942 KBps 4.3125 0.64% 115.108 KBps 8.6875 0.08%
6 230.4 KBps 228.571 KBps 2.1875 0.79% 231.884 KBps 4.3125 0.64%
7 460.8 KBps 470.588 KBps 1.0625 2.12% 457.143 KBps 2.1875 0.79%

ST STM32F446 Series Specifications

General

Brand	ST
Model	STM32F446 Series
Category	Microcontrollers
Language	English