Rev. 1.0, 07/01, page 47 of 372
3.2.3 Interrupt Enable Register 1(IENR1)
IENR1 enables direct transition interrupts, timer A overflow interrupts, and external pin interrupts.
Bit Bit Name Initial Value R/W Description
7 IENDT 0 R/W Direct Transfer Interrupt Enable
When this bit is set to 1, direct transition interrupt requests
are enabled.
6 IENTA 0 R/W Timer A Interrupt Enable
When this bit is set to 1, timer A overflow interrupt
requests are enabled.
5 IENWP 0 R/W Wakeup Interrupt Enable
This bit is an enable bit, which is common to the pins
WKP5 to WKP0. When the bit is set to 1, interrupt
requests are enabled.
4 − 1 − Reserved
This bit is always read as 1, and cannot be modified.
3 IEN3 0 R/W IRQ3 Interrupt Enable
When this bit is set to 1, interrupt requests of the IRQ3 pin
are enabled.
2 IEN2 0 R/W IRQ2 Interrupt Enable
When this bit is set to 1, interrupt requests of the IRQ2 pin
are enabled.
1 IEN1 0 R/W IRQ1 Interrupt Enable
When this bit is set to 1, interrupt requests of the IRQ1 pin
are enabled.
0 IEN0 0 R/W IRQ0 Interrupt Enable
When this bit is set to 1, interrupt requests of the IRQ0 pin
are enabled.
When disabling interrupts by clearing bits in an interrupt enable register, or when clearing bits in
an interrupt flag register, always do so while interrupts are masked(I=1). If the above clear
operations are performed while I=0, and as a result a conflict arises between the clear instruction
and an interrupt request, exception handling for the interrupt will be executed after the clear
instruction has been executed.