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14.4 DTP/External Interrupt Circuit Registers
Reference:
To use an external interrupt input pin (INT7 to INT0) that also serves as an I/O port, set the
bit that also serves the corresponding I/O port of the port direction register (DDR) to "0" to
use the pin as an input port.
The states of the external interrupt input pins (INT7 to INT0) can be read directly using the
port data register (PDR) regardless of the states of the external interrupt request enable bits
(ENIR: EN7 to EN0).
External interrupt request flag bits (ER7 to ER0) of the DTP/interrupt cause register (EIRR)
are set to "1" regardless of the values of the external interrupt request enable bits (ENIR:
EN7 to EN0) when a DTP/external interrupt request signal is detected.
Table 14.4-2 Function Description of Each Bit of the DTP/Interrupt Enable Register (ENIR)
Bit name
Function
bit7
EN7:
External
Interrupt
request enable
bit
This bit enables an interrupt request.
When the external interrupt request flag bit (ER7) of the DTP/interrupt
cause register (EIRR) is set to "1" while this bit is set to "1", an interrupt
request is output.
bit6
EN6:
This bit enables an interrupt request.
When the external interrupt request flag bit (ER6) of the DTP/interrupt
cause register (EIRR) is set to "1" while this bit is set to "1", an interrupt
request is output.
bit5
EN5:
This bit enables an interrupt request.
When the external interrupt request flag bit (ER5) of the DTP/interrupt
cause register (EIRR) is set to "1" while this bit is set to "1", an interrupt
request is output.
bit4
EN4:
This bit enables an interrupt request.
When the external interrupt request flag bit (ER4) of the DTP/interrupt
cause register (EIRR) is set to "1" while this bit is set to "1", an interrupt
request is output.
bit3
EN3:
This bit enables an interrupt request.
When the external interrupt request flag bit (ER3) of the DTP/interrupt
cause register (EIRR) is set to "1" while this bit is set to "1", an interrupt
request is output.
bit2
EN2:
This bit enables an interrupt request.
When the external interrupt request flag bit (ER2) of the DTP/interrupt
cause register (EIRR) is set to "1" while this bit is set to "1", an interrupt
request is output.
bit1
EN1:
This bit enables an interrupt request.
When the external interrupt request flag bit (ER1) of the DTP/interrupt
cause register (EIRR) is set to "1" while this bit is set to "1", an interrupt
request is output.
bit0
EN0:
This bit enables an interrupt request.
When the external interrupt request flag bit (ER0) of the DTP/interrupt
cause register (EIRR) is set to "1" while this bit is set to "1", an interrupt
request is output.