Chapter 3 Interrupts

Interrupt Level and Priority

This LSI allocated vector numbers and interrupt control registers (except reset interrupt) to each inter- rupt. The interrupt level (except reset interrupt, non-maskable interrupt) can be set by software, per each interrupt group. There are three hierarchical interrupt levels. If multiple interrupts have the same priority, the one with the lowest vector number takes priority. For example, if a vector 3 set to level 1 and a vector 4 set to level 2 request interrupts simultaneously, vector 3 interrupt will be accepted.

Interrupt level setting range

Level 0

Level 1

Level 2

Vector 1 (Non-maskable interrupt)

Vectors 2, 5, 6

Vector 3

Vectors 4, 8

Priority Interrupt vector No.

1Vector 1

2Vector 2

3Vector 5

4Vector 6

5Vector 3

6Vector 4

7Vector 8

Figure 3-1-3 Interrupt Priority Outline

Overview III - 7

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Panasonic F77G, MN101C77C user manual Interrupt Priority Outline