
Interrupt Controller
6-8
MC68328 USER’S MANUAL 12/9/97
MOTOROLA
MODULE
INTERRUPT
6
CONTROLLER
PRELIMINARY
this bit is low, IRQ1 is a level-sensitive interrupt. In this case, you must clear the external
source of the interrupt.
0 = Level-sensitive interrupt (default at reset).
1 = Edge-sensitive interrupt.
ET2—RQ2 Edge Trigger Select
When this bit is set, the IRQ2 signal is an edge-triggered interrupt. In edge-triggered mode,
you must write a 1 to the IRQ2 bit in the interrupt status register to clear this interrupt. When
this bit is low, IRQ2 is a level-sensitive interrupt. In this case, you must clear the external
source of the interrupt.
0 = Level-sensitive interrupt (default at reset).
1 = Edge-sensitive interrupt.
ET3—IRQ3 Edge Trigger Select
When this bit is set, the IRQ3 signal is an edge-triggered interrupt. In edge-triggered mode,
you must write a 1 to the IRQ3 bit in the interrupt status register to clear this interrupt. When
this bit is low, IRQ3 is a level-sensitive interrupt. In this case, you must clear the external
source of the interrupt.
0 = Level-sensitive interrupt (default at reset).
1 = Edge-sensitive interrupt.
ET6—IRQ6 Edge Trigger Select
When this bit is set, the IRQ6 signal is an edge-triggered interrupt. In edge-triggered mode,
you must write a 1 to the IRQ6 bit in the interrupt status register to clear this interrupt. When
this bit is low, IRQ6 is a level-sensitive interrupt. In this case, you must clear the external
source of the interrupt.
0 = Level-sensitive interrupt (default at reset).
1 = Edge-sensitive interrupt.
Bits 0–7—Reserved
These bits are reserved and should remain at their default value.
6.5.3 Interrupt Mask Register
The interrupt mask (IMR) is a control register that can mask out a particular interrupt if the
corresponding bit for the interrupt is set. There is one control bit for each interrupt source.
When an interrupt is masked, the interrupt controller will not generate an interrupt request