120
CHAPTER 8 WATCHDOG TIMER
User’s Manual U15104EJ2V0UD
(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
Inadvertent Program Loop Detection Time
2
12
/f
X
(910
µ
s)
2
13
/f
X
(1.82 ms)
2
14
/f
X
(3.64 ms)
2
15
/f
X
(7.28 ms)
2
16
/f
X
(14.6 ms)
2
17
/f
X
(29.1 ms)
2
18
/f
X
(58.3 ms)
2
20
/f
X
(233 ms)
Remarks 1. f
X
: System clock oscillation frequency
2. ( ): f
X
= 4.5 MHz
(2) Interval timer mode
Interrupt requests are generated at the preset time intervals.
Table 8-2. Interval Time
Interval Time
2
12
/f
X
(910
µ
s)
2
13
/f
X
(1.82 ms)
2
14
/f
X
(3.64 ms)
2
15
/f
X
(7.28 ms)
2
16
/f
X
(14.6 ms)
2
17
/f
X
(29.1 ms)
2
18
/f
X
(58.3 ms)
2
20
/f
X
(233 ms)
Remarks 1. f
X
: System clock oscillation frequency
2. ( ): f
X
= 4.5 MHz
Содержание mPD178053
Страница 2: ...2 User s Manual U15104EJ2V0UD MEMO ...