MC68HC908AS60ACFN FREESCALE [Freescale Semiconductor, Inc], MC68HC908AS60ACFN Datasheet - Page 171

• Manufacturer Part Number: MC68HC908AS60ACFN
• Description: M68HC08 Microcontrollers
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

Chapter 17
External Interrupt Module (IRQ)
17.1 Introduction
This chapter describes the nonmaskable external interrupt (IRQ) input.
17.2 Features
Features include:
17.3 Functional Description
A falling edge applied to the external interrupt pin can latch a CPU interrupt request.
the structure of the IRQ module.
Interrupt signals on the IRQ pin are latched into the IRQ latch. An interrupt latch remains set until one of
the following actions occurs:
Freescale Semiconductor
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Dedicated External Interrupt Pin (IRQ)
Hysteresis Buffer
Programmable Edge-Only or Edge- and Level-Interrupt Sensitivity
Automatic Interrupt Acknowledge
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.
MC68HC908AZ60A • MC68HC908AS60A • MC68HC908AS60E Data Sheet, Rev. 6
Figure 17-1
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