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1 eit interrupt levels – FUJITSU MB91F109 FR30 User Manual

Page 78

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54

CHAPTER 2 CPU

2.8.1

EIT Interrupt Levels

The EIT interrupt levels range from 0 to 31, which are managed using five bits.

Interrupt Levels

Table 2.8.1 summarizes the assignments of the EIT interrupt levels.

Operation can be performed on levels 16 to 31.

Undefined-instruction exceptions, coprocessor nonexistent traps, coprocessor error traps, and
INT instructions are not affected by interrupt levels. ILM is not changed either.

Table 2.8-1 Interrupt Level

Level

Cause

Remarks

Binary

Decimal

00000

0

(Reserved by the system)

When the original value of ILM is
one from 16 to 31, no value within
this range can be set in ILM by a
program.

:

:

:

:

:

:

00011

3

(Reserved by the system)

00100

4

INTE instruction

Step-trace-trap

00101

5

(Reserved by the system)

:

:

:

:

:

:

01110

14

(Reserved by the system)

01111

15

NMI (for the user)

10000

16

Interrupt

When ILM is set, user interrupts are
inhibited.

10001

17

Interrupt

:

:

:

:

:

:

11110

30

Interrupt

11111

31

-

When ICR is set, interrupts are
inhibited.