NEC mPD178054 Series User Manual page 120

(1) Watchdog timer mode
An inadvertent program loop is detected. Upon detection of the inadvertent program loop, a non-maskable
interrupt request or reset can be generated.
Table 8-1. Watchdog Timer Inadvertent Program Loop Detection Times
(2) Interval timer mode
Interrupt requests are generated at the preset time intervals.
120
CHAPTER 8 WATCHDOG TIMER
Inadvertent Program Loop Detection Time
(910 µ s)
12
2 /f
X
13
2 /f (1.82 ms)
X
14
2 /f (3.64 ms)
X
15
2 /f (7.28 ms)
X
16
2 /f (14.6 ms)
X
17
2 /f (29.1 ms)
X
18
2 /f (58.3 ms)
X
20
2 /f (233 ms)
X
Remarks 1. f : System clock oscillation frequency
X
2. ( ): f = 4.5 MHz
X
Table 8-2. Interval Time
Interval Time
(910 µ s)
12
2 /f
X
13
2 /f (1.82 ms)
X
14
2 /f (3.64 ms)
X
15
2 /f (7.28 ms)
X
16
2 /f (14.6 ms)
X
17
2 /f (29.1 ms)
X
18
2 /f (58.3 ms)
X
20
2 /f (233 ms)
X
Remarks 1. f : System clock oscillation frequency
X
2. ( ): f = 4.5 MHz
X
User's Manual U15104EJ2V0UD