Hardware manual

Rev. 3.0, 09/98, page 203 of 361
Table 10.4 Examples of BRR Settings in Synchronous Mode
XTAL Frequency (MHz)
2 4 8 10 16 20
Bit
Rate
nNnNnNnNnNnN
100 
250 1 249 2 124 2 249 3 124 
500 1 124 1 249 2 124 2 249 
1k 0 249 1 124 1 249 2 124 
2.5k 0 99 0 199 1 99 1 124 1 199 1 249
5k 0 49 0 99 0 199 0 249 1 99 1 124
10k 0 24 0 49 0 99 0 124 0 199 0 249
25k09019039049079099
50k0409019024039049
100k 0409019024
250k 0 0* 0103040709
500k 0 0* 010304
1M 0 0* 01
2.5M 00*
Notes: Blank: No setting is available.
: A setting is available, but the bit rate is inaccurate.
*: Continuous transfer is not possible.
B = OSC
×
10
6
/[8
×
2
2n
×
(N + 1)]
N: BRR value (0
≤
N
≤
255)
OSC: Crystal oscillator frequency in MHz
B: Baud rate (bits per 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