7. Interrupt controller
A96G140/A96G148/A96A148 User’s manual
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Figure 21. Effective Timing of Multi-Interrupt
Figure 19 shows an example of multi-interrupt processing. While INT1 is served, INT0 which has higher
priority than INT1 is occurred. Then INT0 is served immediately and then the remaining part of INT1
service routine is executed. If the priority level of INT0 is same or lower than INT1, INT0 will be served
after the INT1 service has completed.
An interrupt service routine may be only interrupted by an interrupt of higher priority and, if two interrupts
of different priority occur at the same time, the higher level interrupt will be served first. An interrupt
cannot be interrupted by another interrupt of the same or a lower priority level. If two interrupts of the
same priority level occur simultaneously, the service order for those interrupts is determined by the
scan order.
7.7
Interrupt enable accept timing
Main Program
Service
Occur
INT1 Interrupt
INT1 ISR
Occur
INT0 Interrupt
INT0 ISR
RETI
RETI
Set EA
