Z51F0410 Datasheet, PDF (65/184 Pages) Zilog, Inc. – Z8051 Series 8-Bit Microcontrollers

Z51F0410
Product Specification
Main Program
Service
INT1 ISR
Occur
INT1 Interrupt
Enable INT0
Disable others
EA
Occur
INT0 Interrupt
INT0 ISR
Enable INT0
Enable others
RETI
RETI
Figure 3.6 Execution of Multi Interrupt
Following example is shown to service INT0 routine during INT1 routine in Figure 3.6. In this
example, INT0 interrupt priority is higher than INT1 interrupt priority. If some interrupt is lower than
INT1 priority, it can’t service its interrupt routine.
Example) Software Multi Interrupt:
INT1:
MOV
MOV
:
MOV
MOV
RETI
IE, #81H ; Enable INT0 only
IE1, #00H ; Disable other
IE, #0FFH ; Enable all Interrupts
IE1, #0FFH
PS029502-0212
PRELIMINARY
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