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 14-2. 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 |
