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4 external level register (elvr) – FUJITSU MB91F109 FR30 User Manual

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6.4 External Level Register (ELVR)

6.4

External Level Register (ELVR)

The external level register (ELVR) selects the request detection mode.

External Level Register (ELVR)

The configuration of the external level register (ELVR) is shown below:

The external level register (ELVR) selects the request detection mode.

Two bits each are assigned to INT0 to INT3 and defined as shown in Table 6.4-1.

Suppose the level is selected for the request detection mode. If input is in the active level even
after each EIRR bit is cleared, the corresponding bit is set again.

NMI is always detected at its falling edge (except when it stops).

When it stops, it is detected at the L level.

7

6

5

4

3

2

1

0

ELVR

Address:000099

H

LB3

LA3

LB2

LA2

LB1

LA1

LB0

LA0

00000000

R/W

Initial value

Access

Table 6.4-1 External Interrupt Request Mode

LBx

LAx

Request detection mode

0

0

L level

0

1

H level

1

0

Rising edge

1

1

Falling edge