MC68HC908GP32_08 Datasheet, PDF (101/266 Pages) Freescale Semiconductor, Inc – M68HC08 Microcontrollers

Chapter 9
External Interrupt (IRQ)
9.1 Introduction
The IRQ (external interrupt) module provides a maskable interrupt input.
9.2 Features
Features of the IRQ module include:
• A dedicated external interrupt pin IRQ
• IRQ interrupt control bits
• Programmable edge-only or edge and level interrupt sensitivity
• Automatic interrupt acknowledge
• Internal pullup device
9.3 Functional Description
A low level applied to the external interrupt request (IRQ) pin can latch a CPU interrupt request. Figure 9-1
shows the structure of the IRQ module.
RESET
ACK
IRQ VECTOR
FETCH
DECODER
V_DD
INTERNAL
PULLUP
DEVICE
IRQ
V_DD
CLR
D
Q
CK
SYNCHRONIZER
TO CPU FOR
BIL/BIH
INSTRUCTIONS
IRQF
IRQ
INTERRUPT
REQUEST
IRQ LATCH
IMASK
Freescale Semiconductor
MODE
HIGH
VOLTAGE
DETECT
NOTE: On FLASH devices, high-voltage disables FLASH block protection.
Figure 9-1. IRQ Module Block Diagram
MC68HC908GP32 Data Sheet, Rev. 10
TO MONITOR
MODE SELECT
(NOTE)
101