HD6432633 Datasheet, PDF (840/1453 Pages) Renesas Technology Corp – Series of Microcomputers (MCUs: microcomputer units)

The method of calculating the value to be set in the bit rate register (BRR) from the operating
frequency and bit rate, on the other hand, is shown below. N is an integer, 0 ≤ N ≤ 255, and the
smaller error is specified.
N=
ø
× 10⁶ – 1
S × 2²ⁿ⁺¹ × B
Table 17-6 Examples of BRR Settings for Bit Rate B (bit/s) (When n = 0 and S = 372)
7.1424
10.00 10.7136
13.00
bit/s N Error N Error N Error N Error
9600 0 0.00 1 30
1 25
1 8.99
ø (MHz)
14.2848 16.00
N Error N Error
1 0.00 1 12.01
18.00
N Error
2 15.99
20.00
25.00
28.00
N Error N Error N Error
2 6.60 3 12.49 3 1.99
Table 17-7 Maximum Bit Rate at Various Frequencies (Smart Card Interface Mode)
(when S = 372)
ø (MHz)
Maximum Bit Rate (bit/s)
N
n
7.1424
9600
0
0
10.00
13441
0
0
10.7136
14400
0
0
13.00
17473
0
0
14.2848
19200
0
0
16.00
21505
0
0
18.00
24194
0
0
20.00
26882
0
0
25.00
33602
0
0
28.00
37634
0
0
The bit rate error is given by the following formula:
Error (%) = (
ø
S × 2²ⁿ⁺¹ × B × (N + 1)
× 10⁶ – 1) × 100
786