Panasonic MN103S

Chapter 13
Serial Interface 2
Operation XIII - 31
■ Setting Transfer Speed
Baud rate timers (timer 14, timer 15 and timer 16) can set any transfer rate. Table: 13.3.13 shows an example of
setting transfer speed.
Table:13.3.13 Register for Setting UART Serial Interface Transfer Speed
The value of the timer base register can be set as follows:
Underflow cycle = (Base register set value + 1) × timer clock cycle
Baud rate = 1/ (Underflow cycle × Dividing ratio of serial clock source)
From the above,
Base register set value = Timer clock frequency/(Baud rate × Dividing ratio of serial clock source) - 1
For example, if the desired baud rate is 300 bps at 64 dividing of serial clock source when the timer clock source
is IOCLK/32 (input frequency = 10 MHz, 6 multiplication and IOCLK = MCLK/2) the set value can be deter-
mined as follows:
Base register set value = (10 × 10
6
/32) / (300 × 64) -1
=48
=x’30
The following table shows the clock source at standard transfer rate and the set value of the compare register at
MCLK=60 MHz (IOCLK=MCLK/2).
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Transfer rate should be selected under 300 kbps.
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Description Register Page
Serial clock source setting
(Division ratio setting)
SC2CTR3 XIII-9
Timer selection SIFCLK XII-10