3822_03 Datasheet, PDF (153/328 Pages) Renesas Technology Corp – 8-BIT SINGLE-CHIP MICROCOMPUTER

APPLICATION
2.4 Timer 1, timer 2, and timer 3
sTimer 2
The write operation to the timer 2 counter is controlled by the timer 2 write control bit (bit 2 at address
002916).
(bit 2 = “0”)
As the write operation is the same as that to the timer 1 and the timer 3, refer to the previous
section, “sTimer 1 and timer 3.”
(bit 2 = “1”)
When a value is written to the timer 2, the value is set in the timer 2 latch only. The rewritten value
is reloaded onto the timer 2 counter at the first underflow after rewriting.
Figure 2.4.3 shows an rewriting example of the timer 2 counter and the timer 2 latch.
Rewriting example of timer 2 counter
•UF : Underflow
•RL : Reload
•n : The counter initial value before rewriting
•m : The counter initial value after rewriting
Write “m16” to timer
RL
RL
m16
RL
RL
n16
UF
UF
UF
UF
0016
Timer 2 write
control bit
Interrupt
request bit
Time
1
1
1
1
Interrupt
enable bit
1 : •Clearing by writing “0” to the timer 2 interrupt request bit.
•Clearing by accepting the timer 2 interrupt request when the timer 2 interrupt request
bit is “1.”
Fig. 2.4.3 Rewriting example of timer 2 counter and timer 2 latch (Writing in timer 2 latch only)
3822 GROUP USER’S MANUAL
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