Philips P89LPC907 用户手册

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Philips Semiconductors
User’s Manual - Preliminary -
P89LPC906/907/908
WATCHDOG TIMER
2003 Dec 8     
85
PERIODIC WAKEUP FROM POWER DOWN WITHOUT AN EXTERNAL OSCILLATOR
Without using an external oscillator source, the power consumption required in order to have a periodic wakeup is determined 
by the power consumption of the internal oscillator source used to produce the wakeup.The Real-time clock running from the 
internal RC oscillator can be used. The power consumption of this oscillator is approximately 300uA. Instead, if the WDT is used 
to generate interrupts the current is reduced to approximately 50uA. Whenever the WDT underflows, the device will wake up.