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RTEMS 4.5.1-pre3 On-Line Library


Interrupt Processing Interrupt Levels

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4.4: Interrupt Levels

Thirty-two levels (0-31) of interrupt priorities are supported by the i960CA microprocessor with level thirty-one (31) being the highest priority. Level zero (0) indicates that interrupts are fully enabled. Interrupt requests for interrupts with priorities less than or equal to the current interrupt mask level are ignored.

Although RTEMS supports 256 interrupt levels, the i960CA only supports thirty-two. RTEMS interrupt levels 0 through 31 directly correspond to i960CA interrupt levels. All other RTEMS interrupt levels are undefined and their behavior is unpredictable.


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