MC68HC908GZ8 FREESCALE [Freescale Semiconductor, Inc], MC68HC908GZ8 Datasheet - Page 100

• Manufacturer Part Number: MC68HC908GZ8
• Description: M68HC08 Microcontrollers
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

External Interrupt (IRQ)
When an interrupt pin is both falling-edge and low-level triggered, the interrupt remains set until both of
these events occur:
The vector fetch or software clear may occur before or after the interrupt pin returns to logic 1. As long as
the pin is low, the interrupt request remains pending. A reset will clear the latch and the MODE control bit,
thereby clearing the interrupt even if the pin stays low.
When set, the IMASK bit in the INTSCR mask all external interrupt requests. A latched interrupt request
is not presented to the interrupt priority logic unless the IMASK bit is clear.
100
$001D
Addr.
•
•
Vector fetch or software clear
Return of the interrupt pin to logic 1
IRQ
IRQ Status and Control
Register Name
Register (INTSCR)
The interrupt mask (I) in the condition code register (CCR) masks all
interrupt requests, including external interrupt requests.
DECODER
V
VECTOR
See page 102.
FETCH
DD
RESET
ACK
INTERNAL
PULLUP
DEVICE
Reset:
MC68HC908GZ16 • MC68HC908GZ8 Data Sheet, Rev. 4
Read:
Write:
Figure 8-1. IRQ Module Block Diagram
Figure 8-2. IRQ I/O Register Summary
V
MODE
DD
Bit 7
0
0
D
CK
CLR
= Unimplemented
Q
6
0
0
NOTE
5
0
0
IMASK
SYNCHRONIZER
4
0
0
VOLTAGE
DETECT
HIGH
IRQF
3
0
ACK
2
0
0
IRQF
Freescale Semiconductor
IMASK
1
0
TO CPU FOR
BIL/BIH
INSTRUCTIONS
IRQ
INTERRUPT
REQUEST
TO MODE
SELECT
LOGIC
MODE
Bit 0
0