W78E516DDG Datasheet, PDF (51/90 Pages) Nuvotem Talema – 8-BIT MICROCONTROLLER

W78E516D/W78E058D Data Sheet
one machine cycle, and then hold it low for at least one machine cycle. This is to ensure that the tran-
sition is seen and that interrupt request flag IEn is set. IEn is automatically cleared by the CPU when
the service routine is called.
If the external interrupt is level-activated, the external source must hold the request active until the
requested interrupt is actually generated. If the external interrupt is still asserted when the interrupt
service routine is completed another interrupt will be generated. It is not necessary to clear the inter-
rupt flag IEn when the interrupt is level sensitive, it simply tracks the input pin level.
If an external interrupt is enabled when the W78E516D/W78E058D is put into Power Down or Idle
mode, the interrupt will cause the processor to wake up and resume operation. Refer to the section on
Power Reduction Modes for details.
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Publication Release Date: Feb 15, 2011
Revision A09