Freescale Semiconductor MC68HC908MR32 Manual Do Utilizador
MC68HC908MR32 • MC68HC908MR16 Data Sheet, Rev. 6.1
Freescale Semiconductor
91
Chapter 8
External Interrupt (IRQ)
External Interrupt (IRQ)
8.1 Introduction
This section describes the external interrupt (IRQ) module, which supports external interrupt functions.
8.2 Features
Features of the IRQ module include:
•
A dedicated external interrupt pin, IRQ
•
Hysteresis buffers
8.3 Functional Description
A logic 0 applied to any of the external interrupt pins can latch a CPU interrupt request.
shows
the structure of the IRQ module.
Figure 8-1. IRQ Module Block Diagram
Addr.
Register Name
Bit 7
6
5
4
3
2
1
Bit 0
$003F
IRQ Status/Control Register
(ISCR)
Read:
0
0
0
0
IRQF
0
IMASK1
MODE1
Write:
R
R
R
R
ACK1
Reset:
0
0
0
0
0
0
0
0
R
= Reserved
Figure 8-2. IRQ I/O Register Summary
ACK1
IMASK1
D
Q
CK
CLR
IRQ
HIGH
INTERRUPT
TO MODE
SELECT
LOGIC
SELECT
LOGIC
IRQ
LATCH
REQUEST
IRQ
V
DD
MODE1
VOLTAGE
DETECT
SYNCHRO-
NIZER