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.