All interrupt vectors are assigned to one of three possible priority levels as
shown in the table. An interrupt request from a high priority source will interrupt any
ongoing interrupt handler from a normal priority source. When returning from the high
priority interrupt handler, the execution of the normal priority interrupt handler will
resume.
Table 13-2. Interrupt Priority Levels
| Priority |
Level |
Source |
| Highest |
Non-Maskable Interrupt (NMI) |
Device dependent and statically assigned |
| ... |
High Priority (Level 1) |
One vector is optionally user selectable as Level 1 |
| Lowest |
Normal Priority (Level 0) |
The remaining interrupt vectors |
