Chapter 10 Watchdog Timer; Watchdog Timer Functions - NEC mPD780852 Series Preliminary User's Manual

10.1 Watchdog Timer Functions

The watchdog timer has the following functions.
• Watchdog timer
• Interval timer
Caution Select the watchdog timer mode or the interval timer mode with the watchdog timer mode
register (WDTM).
Figure 10-1 shows the watchdog timer block diagram.
RUN
8 Prescaler
f /2
X
12 13 14 15 16 17
f /2 f /2 f /2 f /2 f /2 f /2 f
X X X X X X
Watchdog timer clock
select register (WDCS)

CHAPTER 10 WATCHDOG TIMER

Figure 10-1. Watchdog Timer Block Diagram
18 20
/2 f /2
X X
3
WDCS2 WDCS1 WDCS0 RUN WDTM4 WDTM3
Internal bus
Preliminary User's Manual U14581EJ3V0UM00
Internal bus
WDTMK
WDTIF
Watchdog timer mode register (WDTM)
INTWDT
Maskable
interrupt request
RESET
INTWDT
Non-maskable
interrupt request
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