Which of the following 8085 microprocessor hardware interrupt has the lowest…
2015
Which of the following 8085 microprocessor hardware interrupt has the lowest priority?
Answer: D. INTR — Answer: INTR has the lowest priority among the 8085 hardware interrupts. Priority order (highest to lowest): TRAP → RST 7.5 → RST 6.5 → RST 5.5 → INTR TRAP:…
- A.
RST 6.5
- B.
RST 7.5
- C.
TRAP
- D.
INTR
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Correct answer: D
Answer: INTR has the lowest priority among the 8085 hardware interrupts.
Priority order (highest to lowest): TRAP → RST 7.5 → RST 6.5 → RST 5.5 → INTR
TRAP: Highest-priority interrupt; non-maskable (cannot be disabled) and vectored.
RST 7.5, RST 6.5, RST 5.5: Vectored, maskable interrupts with decreasing priority in that order.
INTR: General-purpose, non-vectored, maskable interrupt and therefore the lowest in priority. On interrupt acknowledge the external device must supply the interrupting instruction/vector.
Why this matters: knowing which interrupts are vectored versus non-vectored and whether they are maskable helps determine their relative priority and how the CPU responds during an interrupt.