Datasheet

MC68HC908GP32 Data Sheet, Rev. 10
Freescale Semiconductor 101
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.
Figure 9-1. IRQ Module Block Diagram
IMASK
DQ
CK
CLR
IRQ
HIGH
INTERRUPT
TO MONITOR
REQUEST
V
DD
MODE
VOLTAGE
DETECT
IRQF
TO CPU FOR
BIL/BIH
INSTRUCTIONS
INTERNAL ADDRESS BUS
RESET
V
DD
INTERNAL
PULLUP
DEVICE
ACK
IRQ
SYNCHRONIZER
IRQ VECTOR
FETCH
DECODER
IRQ LATCH
MODE SELECT
(NOTE)
NOTE: On FLASH devices, high-voltage disables FLASH block protection.