MC68HC08AS32 Datasheet, PDF (127/280 Pages) Motorola, Inc – M68HC08 Family of 8-bit microcontroller units (MCUs)

Data Sheet — MC68HC08AS32
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
TO CPU FOR
BIL/BIH
INSTRUCTIONS
IRQF
IRQ
INTERRUPT
REQUEST
MC68HC08AS32 — Rev. 4.1
Freescale Semiconductor
MODE
HIGH
VOLTAGE
DETECT
Figure 8-1. IRQ Block Diagram
TO MODE
SELECT
LOGIC
Data Sheet
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