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Chapter 15
Serial Interface Channel UART
User’s Manual U16504EE1V1UD00
Error tolerance range for baud rates
The tolerance range for baud rates depends on the number of bits per frame and the counter’s
division rate [1/(16 + k)].
Table 15-4 describes the relation between the main system clock and the baud rate and
Figure 14-9 shows an example of a baud rate error tolerance range.
Remarks: 1.
f
X
: Oscillation frequency of main system clock
2.
n: Value set via TPS00 to TPS02 (1
≤
n
≤
8)
3.
k: Value set via MDL00 to MDL03 (0
≤
k
≤
14)
Figure 15-9:
Error Tolerance (when k = 0), including Sampling Errors
Remark:
T: 5-bit counter’s source clock cycle
Table 15-4:
Relation between Main System Clock and Baud Rate
Baud rate
(bps)
f
X
= 8.386 MHz
f
X
= 8.000 MHz
f
X
= 5.000 MHz
f
X
= 4.1943 MHz
BRGCO
ERR (%)
BRGCO
ERR (%)
BRGCO
ERR (%)
BRGCO
ERR (%)
600
7BH
1.10
7AH
0.16
70H
1.73
6BH
1.14
1200
6BH
1.10
6AH
0.16
60H
1.73
5BH
1.14
2400
5BH
1.10
5AH
0.16
50H
1.73
4BH
1.14
4800
4BH
1.10
4AH
0.16
40H
1.73
3BH
1.14
9600
3BH
1.10
3AH
0.16
30H
1.73
2BH
1.14
19200
2BH
-1.3
2AH
0.16
20H
1.73
1BH
1.14
31250
21H
1.10
20H
0
14H
0
11H
-1.31
38400
1BH
1.10
1AH
0.16
10H
1.73
0BH
1.14
76800
0BH
1.10
0AH
0.16
00H
1.73
-
-
115200
02H
1.03
01H
0.16
-
-
-
-
Basic timing
(clock cycle T)
START
D0
D7
P
STOP
High-speed clock
(clock cycle T’)
enabling normal
reception
START
D0
D7
P
STOP
Low-speed clock
(clock cycle T”)
enabling normal
reception
START
D0
D7
P
STOP
32T
64T
256T
288T
320T
352T
Ideal
sampling
point
304T
336T
30.45T
60.9T
304.5T
15.5T
15.5T
0.5T
Sampling error
33.55T
67.1T
301.95T
335.5T
Baud rate error tolerance (when k = 0) =
= 4.8438 (%)
±15.5
×
100
320