Universal synchronous asynchronous receiver transmitter (USART)
RM0090
980/1731
DocID018909 Rev 11
11
1.792 MBps
1.826 MBps
1.4375
1.9
1.787 MBps
2.9375
0.27
12
1.8432
MBps
1.826 MBps
1.4375
0.93
1.826 MBps
2.875
0.93
13
3.584 MBps
N.A
N.A
N.A
3.652 MBps
1.4375
1.9
14
3.6864
MBps
N.A
N.A
N.A
3.652 MBps
1.4375
0.93
15
7.168 MBps
N.A
N.A
N.A
N.A
N.A
N.A
16
7.3728
MBps
N.A
N.A
N.A
N.A
N.A
N.A
18
9 MBps
N.A
N.A
N.A
N.A
N.A
N.A
20
10.5 MBps
N.A
N.A
N.A
N.A
N.A
N.A
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 141. Error calculation for programmed baud rates at f
PCLK
= 42 MHz or f
PCLK
= 84 Hz,
oversampling by 16
(1)(2)
(continued)
Oversampling by 16 (OVER8=0)
Baud rate
f
PCLK
= 42 MHz
f
PCLK
= 84 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 142. Error calculation for programmed baud rates at f
PCLK
= 42 MHz or f
PCLK
= 84 MHz,
oversampling by 8
(1)(2)
Oversampling by 8 (OVER8=1)
Baud rate
f
PCLK
= 42 MHz
f
PCLK
= 84 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.
1.2 KBps
1.2 KBps
4375
0
1.2 KBps
8750
0
2.
2.4 KBps
2.4 KBps
2187.5
0
2.4 KBps
4375
0
3.
9.6 KBps
9.6 KBps
546.875
0
9.6 KBps
1093.75
0
4.
19.2 KBps
19.195 KBps
273.5
0.02
19.2 KBps
546.875
0
5.
38.4 KBps
38.391 KBps
136.75
0.02
38.391 KBps
273.5
0.02
6.
57.6 KBps
57.613 KBps
91.125
0.02
57.613 KBps
182.25
0.02
7.
115.2 KBps
115.068 KBps
45.625
0.11
115.226 KBps
91.125
0.02
8.
230.4 KBps
230.769 KBps
22.75
0.11
230.137 KBps
45.625
0.11