M38203M4 Datasheet, PDF (161/344 Pages) Mitsubishi Electric Semiconductor – 8-BIT SINGLE-CHIP MICROCOMPUTER

APPLICATION
2.3 Timer X and timer Y
2.3.5 Application examples
(1) Pulse output mode : Piezoelectric buzzer output
Outline : The rectangular waveform output function of a timer is applied for a piezoelectric buzzer
output.
Specifications : •The rectangular waveform which is divided clock f(XIN) = 8 MHz up to about 2 kHz
is output from the P54/CNTR0 pin.
•The level of the P54/CNTR0 pin fixes to “H” while a piezoelectric buzzer output is
stopped.
Figure 2.3.32 shows an example of a peripheral circuit, Figure 2.3.33, a connection of the timer and
a setting of the division ratio, Figure 2.3.34, the setting of the related registers, and Figure 2.3.35, the
control procedure.
The “H” level is output while a piezoelectric buzzer output is stopped.
3820 group
250 µ s 250 µ s
Set a division ratio so that the
underflow cycle of the timer X
is this value.
Fig. 2.3.32 Example of peripheral circuit
P54/CNTR0
PiPiPi....
f(XIN) = 8 MHz
Fix
Timer X
1/16
1/125
CNTR0
Fig. 2.3.33 Connection of timer and setting of division ratio
3820 GROUP USER’S MANUAL
2–75