Posted on June 28, 2011 at 12:19Pre-emptive: an interrupt source having higher pre-emptive priority would interrupt the service routine being processing a previously occured interrupt with a lower pre-priority. The higher interrupt having been processed, the CPU returns to the interrupted service routine of the lower priority.
Sub: should two or more interrupts having the same pre-emptive priority occure
simultaneously (or be pending),
an interrupt with the higher sub-priority would be serviced first, and they cannot interrupt each other.
Remember: the lower the value of the priority, the higher it is; the highest (user) priority is '0', the lowest - '15'.
