ST STM32F40 Series User Manual

RM0090 Universal synchronous asynchronous receiver transmitter (USART)
Doc ID 018909 Rev 4 758/1422
11 2 MBps NA NA NA NA NA NA
12 3 MBps NA NA NA NA NA NA
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 109. Error calculation for programmed baud rates at f
PCLK
= 8 MHz or f
PCLK
=12 MHz,
oversampling by 8
(1)
(continued)
Oversampling by 8 (OVER8 = 1)
Baud rate f
PCLK
= 8 MHz f
PCLK
= 12 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
Table 110. Error calculation for programmed baud rates at f
PCLK
= 16 MHz or f
PCLK
= 24 MHz,
oversampling by 16
(1)
Oversampling by 16 (OVER8 = 0)
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 833.3125 0 1.2 1250 0
2 2.4 KBps 2.4 KBps 416.6875 0 2.4 625 0
3 9.6 KBps 9.598 KBps 104.1875 0.02 9.6 156.25 0
4 19.2 KBps 19.208 KBps 52.0625 0.04 19.2 78.125 0
5 38.4 KBps 38.369 KBps 26.0625 0.08 38.4 39.0625 0
6 57.6 KBps 57.554 KBps 17.375 0.08 57.554 26.0625 0.08
7 115.2 KBps 115.108 KBps 8.6875 0.08 115.385 13 0.16
8 230.4 KBps 231.884 KBps 4.3125 0.64 230.769 6.5 0.16
9 460.8 KBps 457.143 KBps 2.1875 0.79 461.538 3.25 0.16
10 921.6 KBps 941.176 KBps 1.0625 2.12 923.077 1.625 0.16
11 2 MBps NA NA NA NA NA NA
12 3 MBps NA NA NA NA NA NA
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.

ST STM32F40 Series Specifications

General

Brand	ST
Model	STM32F40 Series
Category	Microcontrollers
Language	English