NEC mPD780973 Series Preliminary User's Manual page 137

CHAPTER 10 WATCH TIMER
Figure 10-3. Operation Timing of Watch Timer/Interval Timer
5-bit counter
0H
Overflow Overflow
Start
Count clock
9
f or f /2
W W
Watch timer
interrupt INTWT
Interrupt time of watch timer (0.25 s) Interrupt time of watch timer (0.25 s)
Interval timer
interrupt INTWTI
Interval timer T
(T)
Remark f : Watch timer clock frequency
W
( ) : f = 4.09 kHz (f = 8.38 MHz)
W X
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