MC68HC08AS32A Datasheet, PDF (135/296 Pages) Motorola, Inc – Microcontrollers

Freescale Semiconductor, Inc.
Data Sheet — MC68HC08AS32A
Section 8. External Interrupt (IRQ)
8.1 Introduction
This section describes the non-maskable external interrupt (IRQ) input.
8.2 Features
Features of the IRQ include:
• Dedicated external interrupt pin (IRQ)
• Hysteresis buffer
• Programmable edge-only or edge and level interrupt sensitivity
• Automatic interrupt acknowledge
8.3 Functional Description
A logic 0 applied to the external interrupt pin can latch a CPU interrupt request.
Figure 8-1 shows the structure of the IRQ module.
ACK
VECTOR
FETCH
DECODER
IRQ
V_DD
D ^CLR Q
CK
IRQ
LATCH
SYNCHRO-
NIZER
IMASK
MODE
HIGH
VOLTAGE
DETECT
Figure 8-1. IRQ Block Diagram
TO CPU FOR
BIL/BIH
INSTRUCTIONS
IRQF
IRQ
INTERRUPT
REQUEST
TO MODE
SELECT
LOGIC
MC68HC08AS32A — Rev. 1
MOTOROLA
External Interrupt (IRQ)
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Data Sheet
135