7470_N Datasheet, PDF (83/354 Pages) Renesas Technology Corp – 8-BIT SINGLE-CHIP MICROCOMPUTER 740 FAMILY / 7470 SERIES

HARDWARE
1.12 Timers
Count period
Count period T(s) = 1 ÷ count source frequency ! (the timer initial value + 1)
Timer mode operation example
• OF: Overflow
• RL: Reload
• n: Timer initial value
“1” is written “0” is written
Timer 1 count stop bit
Timer 1 count source
(n-1)16
RL
RL
Down count
RL
RL Count stop
Count restart
OF
OF
OF
OF
FF16
T
Timer 1 interrupt
request bit
A
A
A
A
Timer 1 interrupt
enable bit
A : • Clearing by writing “0” to the timer interrupt request bit.
• Clearing by accepting the timer interrupt request when the timer interrupt enable bit is “1.”
Time
Fig. 1.12.3 Example of timer mode operation
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7470/7471/7477/7478 GROUP USER’S MANUAL