Question

Differentiate between Maskable and Non-maskable interrupts. (Any three points)

Answer 1

Sr. No.	Feature	Maskable interrupt	Non‑maskable interrupt
1.	Masking (can be disabled?)	Can be disabled (masked) by software via interrupt‑enable logic or individual mask bits (e.g., EI/DI and RST mask bits in the 8085).	Cannot be disabled by normal software; the CPU recognises it even when mask bits/interrupt enable are cleared.
2.	Priority & purpose	Lower priority; used for ordinary peripheral requests and routine service calls.	Highest priority; reserved for urgent/critical conditions that must be serviced (e.g., TRAP in the 8085).
3.	Control & handling	Controlled by an interrupt‑enable flip‑flop or mask bits if masked, the processor will ignore the request until unmasked.	Bypasses/ignores the mask logic and is usually latched or immediately recognised until serviced.