Datasheet

External Interrupt (IRQ)
Functional Description
MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Technical Data
Freescale Semiconductor External Interrupt (IRQ) 221
Figure 13-1. IRQ Module Block Diagram
Addr. Register Name Bit 7 6 5 4 3 2 1 Bit 0
$001C
IRQ Option Control Register
(IOCR)
Read: 0 0 0 0 0 PTE4IF
PTE4IE IRQPD
Write:
Reset:00000000
$001E
IRQ Status and Control Register
(ISCR)
Read: 0 0 0 0 IRQF 0
IMASK MODE
Write:
ACK
Reset:00000000
= Unimplemented
Figure 13-2. IRQ I/O Register Summary
ACK
IMASK
DQ
CK
CLR
IRQ
HIGH
INTERRUPT
TO MODE
SELECT
LOGIC
IRQ
FF
REQUEST
"1"
MODE
VOLTAGE
DETECT
SYNCHRO-
NIZER
IRQF
TO CPU FOR
BIL/BIH
INSTRUCTIONS
VECTOR
FETCH
DECODER
INTERNAL ADDRESS BUS
RESET
V
DD
I
NTERNAL
PULLUP
DEVICE
DQ
CK
CLR
"1"
PTE4IF
PTE4IE
PTE4
IRQ
IRQPD
READ IOCR
TO PTE4 PULLUP
ENABLE CIRCUITRY