FUJITSU Semiconductor Controller MB89950/950A - Manual (Page 210)

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CHAPTER 10 UART
Table 10.1-4 "Transfer cycle and transfer rate by baud rate generator" is shown the example of baud rate
when using the dedicated baud rate generator.
Furthermore, Figure 10.1-1 "Sample calculation of the baud rate" shows the formula of calculating the baud
rate.
Figure 10.1-1 Sample calculation of the baud rate
Table 10.1-4 Transfer cycle and transfer rate by baud rate generator
RC2 RC1 RC0 Division ratio
Baud rate (bps)
4.912 MHz 5 MHz Input clock
1/4 1/4 1/65 PDS division
1/64 1/8 1/16 CS1, CS0, CR division
0 0 0 20 9600 78125 2404
0 0 1 21 4800 39063 1202
0 1 0 22 2400 19531 601
0 1 1 23 1200 9766 300
1 0 0 24 600 4883 150
1 0 1 25 300 2441 75
1 1 0 26 150 1221 38
1 1 1 27 75 610 19
Baud rate value =
F CH
2
X
CPU cloc k
X
CR, CS1, CS0
Transfer clock divider
PDS1, PDS0
Input clock divider
RC2, RC1, RC0
Baud rate divider
X
F CH : Main clock oscillation frequency