RTEMS CPU Architecture Supplement
Eight levels (0-7) of interrupt priorities are supported by XXX family members with level seven (7) 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 XXX family only supports eight. RTEMS interrupt levels 0 through 7 directly correspond to XXX interrupt levels. All other RTEMS interrupt levels are undefined and their behavior is unpredictable.
RTEMS CPU Architecture Supplement
Copyright © 1988-2004 OAR Corporation