NEC PD17062 - Manual (Page 124)

124
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PD17062
11.9 MULTIPLE INTERRUPTS
The multiple interrupt function is used to process interrupt C or D while another interrupt from source A
or B is being processed as shown in Fig. 11-6.
The interrupt depth at this time is called the interrupt level.
Note the following regarding the multiple interrupt function.
(1) Interrupt source priorities
(2) Interrupt level restriction by an interrupt stack
(3) Interrupt level restriction by the address stack register
(4) System or control register saving
See Sections 11.9.1 to 11.9.4 for details.
Fig. 11-6 Example of Multiple Interrupts
MAIN B D
A B
C
Interrupt level 2 Main routine Interrupt level 1