NEC mPD780973 Series Preliminary User's Manual page 140

(1) Watchdog timer mode
A runaway is detected. Upon detection of the runaway, a non-maskable interrupt request or RESET can be
generated.
Remarks 1. f : Main system clock oscillation frequency
X
2. Figures in parentheses apply to operation with f
(2) Interval timer mode
Interrupt requests are generated at preset time intervals.
Remarks 1. f : Main system clock oscillation frequency
X
2. Figures in parentheses apply to operation with f
140
CHAPTER 11 WATCHDOG TIMER
Table 11-1. Watchdog Timer Runaway Detection Time
Runaway Detection Time
(489 µ s)
× 1/f
12
2
X
× 1/f (978 µ s)
13
2
X
× 1/f
14
2 (1.96 ms)
X
× 1/f
15
2 (3.91 ms)
X
× 1/f
16
2 (7.82 ms)
X
× 1/f
17
2 (15.6 ms)
X
× 1/f
18
2 (31.3 ms)
X
× 1/f
20
2 (125 ms)
X
Table 11-2. Interval Time
Interval Time
× 1/f (489 µ s)
12
2
X
× 1/f (978 µ s)
13
2
X
× 1/f
14
2 (1.96 ms)
X
× 1/f
15
2 (3.91 ms)
X
× 1/f
16
2 (7.82 ms)
X
× 1/f
17
2 (15.6 ms)
X
× 1/f
18
2 (31.3 ms)
X
× 1/f
20
2 (125 ms)
X
= 8.38 MHz.
X
= 8.38 MHz.
X