CHAPTER 15 SERIAL INTERFACE UART6
User’s Manual U17260EJ6V0UD
388
(2) Error of baud rate
The baud rate error can be calculated by the following expression.
Error (%) =
1 × 100 [%]
Cautions 1. Keep the baud rate error during transmission to within the permissible error range at the
reception destination.
2. Make sure that the baud rate error during reception satisfies the range shown in (4)
Permissible baud rate range during reception.
Example: Frequency of base clock = 10 MHz = 10,000,000 Hz
Set value of MDL67 to MDL60 bits of BRGC6 register = 00100001B (k = 33)
Target baud rate = 153600 bps
Baud rate = 10 M / (2
× 33)
= 10000000 / (2
× 33) = 151,515 [bps]
Error = (151515/153600
1) × 100
=
1.357 [%]
(3) Example of setting baud rate
Table 15-5. Set Data of Baud Rate Generator
fPRS = 2.0 MHz
fPRS = 5.0 MHz
fPRS = 10.0 MHz
fPRS = 20.0 MHz
Baud
Rate
[bps]
TPS63-
TPS60
k
Calculated
Value
ERR
[%]
TPS63-
TPS60
k
Calculated
Value
ERR
[%]
TPS63-
TPS60
k
Calculated
Value
ERR
[%]
TPS63-
TPS60
k
Calculated
Value
ERR
[%]
300
8H
13
301
0.16
7H
65
301
0.16
8H
65
301
0.16
9H
65
301
0.16
600
7H
13
601
0.16
6H
65
601
0.16
7H
65
601
0.16
8H
65
601
0.16
1200
6H
13
1202
0.16
5H
65
1202
0.16
6H
65
1202
0.16
7H
65
1202
0.16
2400
5H
13
2404
0.16
4H
65
2404
0.16
5H
65
2404
0.16
6H
65
2404
0.16
4800
4H
13
4808
0.16
3H
65
4808
0.16
4H
65
4808
0.16
5H
65
4808
0.16
9600
3H
13
9615
0.16
2H
65
9615
0.16
3H
65
9615
0.16
4H
65
9615
0.16
19200
2H
13
19231
0.16
1H
65
19231
0.16
2H
65
19231
0.16
3H
65
19231
0.16
24000
1H
21
23810
0.79
3H
13
24038
0.16
4H
13
24038
0.16
5H
13
24038
0.16
31250
1H
16
31250
0
4H
5
31250
0
5H
5
31250
0
6H
5
31250
0
38400
1H
13
38462
0.16
0H
65
38462
0.16
1H
65
38462
0.16
2H
65
38462
0.16
48000
0H
21
47619
0.79
2H
13
48077
0.16
3H
13
48077
0.16
4H
13
48077
0.16
76800
0H
13
76923
0.16
0H
33
75758
1.36
0H
65
76923
0.16
1H
65
76923
0.16
115200
0H
9
111111
3.55
1H
11
113636
1.36
0H
43
116279
0.94
0H
87
114943
0.22
153600
1H
8
156250
1.73
0H
33
151515
1.36
1H
33
151515
1.36
312500
0H
8
312500
0
1H
8
312500
0
2H
8
312500
0
625000
0H
4
625000
0
1H
4
625000
0
2H
4
625000
0
Remark
TPS63 to TPS60: Bits 3 to 0 of clock selection register 6 (CKSR6) (setting of base clock (fXCLK6))
k:
Value set by MDL67 to MDL60 bits of baud rate generator control register 6
(BRGC6) (k = 4, 5, 6, ..., 255)
fPRS:
Peripheral hardware clock frequency
ERR:
Baud rate error
Actual baud rate (baud rate with error)
Desired baud rate (correct baud rate)
<R>