CHAPTER 10 SERIAL INTERFACE FUNCTION
User’s Manual U15195EJ5V0UD
471
<4> Baud rate setting example
In an actual system, the output of a prescaler module, etc. is connected to the input clock. Table 10-
8 shows the baud rate generator setting data at this time.
Table 10-8. Baud Rate Generator Setting Data (BRG =
f
XX
/2)
(a) When f
XX
= 32 MHz
Target Baud Rate
Actual Baud Rate
Synchronous
Mode
Asynchronous
Mode
Synchronous
Mode
Asynchronous
Mode
BGCSm Bit
(m = 0, 1)
PRSCM1
Register Setting
Value
Error
4,800 300
4,807.692
300.4808
3 208
0.16
9,600 600
9,615.385
600.9615
3 104
0.16
19,200 1,200
19,230.77
1,201.923 3
52 0.16
38,400 2,400
38,461.54
2,403.846 3
26 0.16
76,800 4,800
76,923.08
4,807.692 3
13 0.16
153,600 9,600 153,846.2
9,615.385 2
13 0.16
166,400 10,400 166,666.7
10,416.67 1
24
0.16
307,200 19,200 307,692.3
19,230.77 1
13
0.16
614,400 38,400 615,384.6
38,461.54 0
13
0.16
Not possible
76,800
−
71,428.57 0
7
−
6.99
Not possible
153,600
−
166,666.7 0
3 8.51
(b) When f
XX
= 40 MHz
Target Baud Rate
Actual Baud Rate
Synchronous
Mode
Asynchronous
Mode
Synchronous
Mode
Asynchronous
Mode
BGCSm Bit
(m = 0, 1)
PRSCM1
Register Setting
Value
Error
4,800 300
4,882.813
305.1758
3 256
1.73
9,600 600
9,615.385
600.9615
3 130
0.16
19,200 1,200
19,230.77
1,201.923 3
65 0.16
38,400 2,400
38,461.54
2,403.846 2
65 0.16
76,800 4,800
76,923.08
4,807.692 1
65 0.16
153,600 9,600 153,846.2
9,615.385 0
65 0.16
166,400 10,400 166,666.7
10,416.67 0
60
0.16
307,200 19,200 303,030.3
18,939.39 0
33
−
1.36
614,400 38,400 625,000 39,062.5 0
16
1.73
Not possible
76,800
−
78,125 0 8 1.73
Not possible
153,600
−
156,250 0
4 1.73