MC80F0204 Datasheet, PDF (89/126 Pages) List of Unclassifed Manufacturers – 8-BIT SINGLE-CHIP MICROCONTROLLERS

Preliminary
MC80F0104/0204
be serviced even if certain interrupt is in progress.
Main Program
service
TIMER 1
service
Occur
TIMER1 interrupt
enable INT0
disable other
EI
Occur
INT0
INT0
service
enable INT0
enable other
In this example, the INT0 interrupt can be serviced without any
pending, even TIMER1 is in progress.
Because of re-setting the interrupt enable registers IENH,IENL
and master enable “EI” in the TIMER1 routine.
Figure 18-6 Execution of Multi Interrupt
Example: During Timer1 interrupt is in progress, INT0 in-
terrupt serviced without any suspend.
TIMER1: PUSH
PUSH
PUSH
LDM
LDM
EI
:
:
A
X
Y
IENH,#80H
IENL,#0
;Enable INT0 only
;Disable other int.
;Enable Interrupt
:
:
:
:
LDM
LDM
POP
POP
POP
RETI
IENH,#0FFH
IENL,#0FFH
Y
X
A
;Enable all interrupts
Mar. 2005 Ver 0.2
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