NEC 78K0/KD1 Series User Manual page 210

Table 10-2. Mask Option Setting and Watchdog Timer Operation Mode
Watchdog timer clock
source
Operation after reset
Operation mode selection
Features
Notes 1. As long as power is being supplied, Ring-OSC oscillation cannot be stopped (except in the reset
period).
2. Clock supply to the watchdog timer is stopped in accordance with the watchdog timer clock
source as follows:
<1> When the clock source is f
Clock supply to the watchdog timer is stopped while f
instruction execution, and during the oscillation stabilization time.
<2> When the clock source is f
Clock supply to the watchdog timer is stopped if f
instruction execution when the CPU clock is f
execution.
Remarks 1. f : Ring-OSC clock oscillation frequency
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2. f : X1 input clock oscillation frequency
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CHAPTER 10 WATCHDOG TIMER
Ring-OSC Cannot Be Stopped
Note 1
Fixed to f .
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Operation starts with the maximum
18
interval (f /2 ).
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The interval can be changed only
once.
• The watchdog timer cannot be
stopped.
• Current in STOP mode ≅ 10 µ A
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Preliminary User's Manual U16315EJ1V0UD
Mask Option
Ring-OSC Can Be Stopped by Software
• Selectable by software (f
stopped)
• When reset is released: f
Operation starts with maximum
18
interval (f /2 ).
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The clock selection/interval can be
changed only once.
The watchdog timer can be stopped in
Note 2
standby mode .
is stopped, during HALT/STOP
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is stopped by software before STOP
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and during HALT/STOP instruction
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, f or
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