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Wednesday, May 18, 2011

8259 Operating Modes




MODES OF 8259


1) FULLY NESTED MODE


This is a general purpose mode where all IR's are arranged in highes to lowest.
IR0 highest and IR7 lowest.




2) AUTOMATIC ROTATION MODE


In this mode a device after being serviced receives the lowest priority.


3) SPECIFIC ROTATION MODE


In this user can select any IR for lowest priority thus fixing all priorities.

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