Hardware manual

Rev. 3.0, 09/98, page 202 of 361
Table 10.3 Examples of BRR Settings in Asynchronous Mode (4)
XTAL Frequency (MHz)
14.7456 16 19.6608 20
Bit
Rate n N
Error
(%) n N
Error
(%) n N
Error
(%) n N
Error
(%)
110 2 130 −0.07 2 141 +0.03 2 174 −0.26 2 177 −0.25
150 2 95 0 2 103 +0.16 2 127 0 2 129 +0.16
300 1 191 0 1 207 +0.16 1 255 0 2 64 +0.16
600 1 95 0 1 103 +0.16 1 127 0 1 129 +0.16
1200 0 191 0 0 207 +0.16 0 255 0 1 64 +0.16
2400 0 95 0 0 103 +0.16 0 127 0 0 129 +0.16
4800 0 47 0 0 51 +0.16 0 63 0 0 64 +0.16
9600 0 23 0 0 25 +0.16 0 31 0 0 32 −1.36
19200 0 11 0 0 12 +0.16 0 15 0 0 15 +1.73
31250 07009−1.70 0 9 0
38400 0 5 0 07007+1.73
Note: If possible, the error should be within 1%.
OSC
B =
64 × 2
2n
× (N + 1)
× 10
6
OSC × 10
6
N =
64 × 2
2n
× B
−1
N: BRR value (0 ≤ N ≤ 255)
OSC: Crystal oscillator frequency in MHz
B: Baud rate (bits/second)
n: Internal clock source (0, 1, 2, or 3)
The meaning of n is given by the table below:
n CKS1 CKS0 Clock
000φ
101φ/4
210φ/16
311φ/64