Universal synchronous asynchronous receiver transmitter (USART)
RM0090
978/1731
DocID018909 Rev 11
8.
896 KBps
909.091 KBps 2.0625
1.46%
895.522 KBps 4.1875
0.05%
9.
921.6 KBps
909.091 KBps 2.0625
1.36%
923.077 KBps 4.0625
0.16%
10.
1.792 MBps 1.1764 MBps
1.0625
1.52%
1.8182 MBps
2.0625
1.36%
11.
1.8432
MBps
1.8750 MBps
1.0000
1.73%
1.8182 MBps
2.0625
1.52%
12.
3.584 MBps NA
NA
NA
3.2594 MBps
1.0625
1.52%
13.
3.6864
MBps
NA
NA
NA
3.7500 MBps
1.0000
1.73%
14.
7.168 MBps NA
NA
NA
NA
NA
NA
15.
7.3728
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.
2. Only USART1 and USART6 are clocked with PCLK2. Other USARTs are clocked with PCLK1. Refer to the device
datasheets for the maximum values for PCLK1 and PCLK2.
Table 139. Error calculation for programmed baud rates at f
PCLK
= 30 MHz or f
PCLK
= 60 MHz,
oversampling by 16
(1)(2)
(continued)
Oversampling by 16 (OVER8=0)
Baud rate
f
PCLK
= 30 MHz
f
PCLK
= 60 MHz
S.No
Desired
Actual
Value
programme
d in the
baud rate
register
% Error =
(Calculated -
Desired)B.Rate
/Desired B.Rate
Actual
Value
programmed
in the baud
rate register
%
Error
Table 140. Error calculation for programmed baud rates at f
PCLK
= 30 MHz or f
PCLK
= 60 MHz,
oversampling by 8
(1)
(2)
Oversampling by 8 (OVER8=1)
Baud rate
f
PCLK
= 30 MHz
f
PCLK
=60 MHz
S.No
Desired
Actual
Value
programme
d 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
1562.5000
0.00%
2.400 KBps
3125.0000
0.00%
2.
9.6 KBps
9.600 KBps
390.6250
0.00%
9.600 KBps
781.2500
0.00%
3.
19.2 KBps
19.194 KBps
195.3750
0.03%
19.200 KBps
390.6250
0.00%
4.
57.6 KBps
57.582 KBps
65.1250
0.16%
57.582 KBps
130.2500
0.03%
5.
115.2 KBps
115.385 KBps
32.5000
0.16%
115.163 KBps 65.1250
0.03%
6.
230.4 KBps
230.769 KBps
16.2500
0.16%
230.769 KBps 32.5000
0.16%
7.
460.8 KBps
461.538 KBps
8.1250
0.16%
461.538 KBps 16.2500
0.16%
8.
896 KBps
909.091 KBps
4.1250
1.46%
895.522 KBps 8.3750
0.05%