MC68HC908AZ32ACFU MOTOROLA [Motorola, Inc], MC68HC908AZ32ACFU Datasheet - Page 200

• Manufacturer Part Number: MC68HC908AZ32ACFU
• Description: Microcontrollers
• Manufacturer: MOTOROLA [Motorola, Inc]

External Interrupt Module (IRQ1)
Advance Information
200
IRQ1
DECODER
VECTOR
FETCH
ACK
Interrupt signals on the IRQ1 pin are latched into the IRQ latch. An
interrupt latch remains set until one of the following actions occurs:
The external interrupt pin is falling-edge triggered and is software-
configurable to be both falling-edge and low-level triggered. The MODE
bit in the ISCR controls the triggering sensitivity of the IRQ1 pin.
When an interrupt pin is edge-triggered only, the interrupt latch remains
set until a vector fetch, software clear, or reset occurs.
Freescale Semiconductor, Inc.
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For More Information On This Product,
V
MODE
DD
Vector fetch — A vector fetch automatically generates an interrupt
acknowledge signal that clears the latch that caused the vector
fetch.
Software clear — Software can clear an interrupt latch by writing
to the appropriate acknowledge bit in the interrupt status and
control register (ISCR). Writing a logic 1 to the ACK bit clears the
IRQ latch.
Reset — A reset automatically clears both interrupt latches.
Figure 15-1. IRQ Block Diagram
D
CK
External Interrupt Module (IRQ1)
LATCH
CLR
IRQ
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Q
IMASK
SYNCHRO-
VOLTAGE
DETECT
NIZER
HIGH
68HC908AZ32A — Rev 0.0
IRQF
TO CPU FOR
BIL/BIH
INSTRUCTIONS
IRQ
INTERRUPT
REQUEST
TO MODE
SELECT
LOGIC
MOTOROLA