1 external interrupt control register (eic) – FUJITSU Semiconductor Controller MB89950/950A User Manual

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CHAPTER 11 EXTERNAL INTERRUPT CIRCUIT (EDGE)

11.3.1

External Interrupt Control Register (EIC)

External interrupt control register (EIC) is used to select the edge polarity and to control
interrupts for external interrupt pins (INT0, INT1).

External interrupt control register (EIC)

Figure 11.3-3 External interrupt control register (EIC)

Address

Initial value

0030

H

EIR1

SL11

SL10

EIE1

EIR0

SL01

SL00

EIE0

00000000

B

R/W

R/W

R/W

R/W

R/W

R/W

R/W

R/W

EIE0

INT0 interrupt request enable bit

0

Disables output of interrupt requests.

1

Enables output of interrupt requests.

SL01 SL00

INT0 edge polarity selection bits

0

0

No edge detection

0

1

Rising edge

1

0

Falling edge

1

1

Both edge

EIR0

INT0 external interrupt request flag bit

Read

Write

0

The specified edge has not been detected.

Clears this bit.

1

The specified edge has been

No effect. The bit does not change.

EIE1

INT1 interrupt request enable bit

0

Disables output of interrupt requests.

1

Enables output of interrupt requests.

SL11 SL10

INT1 edge polarity selection bits

0

0

No edge detection

0

1

Rising edge

1

0

Falling edge

1

1

Both edge

EIR1

INT1 external interrupt request flag bit

Read

Write

0

The specified edge has not been

Clears this bit.

1

The specified edge has been

No effect. The bit does not change.

R/W : Readable and writable

: Initial value

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

detected.

detected.

detected.

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