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8085 Interrupts MCQs

Practice 8085 Interrupts MCQs with four options, answers and explanations for focused Electronics & Telecommunication Engineering revision.

Question 1
Microprocessors & Microcontrollers8085 Interrupts

Which 8085 interrupt has the highest hardware priority?

  • AINTR
  • BRST 5.5
  • CRST 6.5
  • DTRAP
Report an error
Correct Answer: D. TRAP
Explanation: TRAP is the highest-priority hardware interrupt in the 8085.
Reference: Standard microprocessors and microcontrollers: 8085 interrupts
Question 2
Microprocessors & Microcontrollers8085 Interrupts

Which 8085 hardware interrupt is non-maskable?

  • ATRAP
  • BRST 7.5
  • CRST 6.5
  • DINTR
Report an error
Correct Answer: A. TRAP
Explanation: TRAP cannot be disabled by the normal interrupt masking mechanism and is therefore non-maskable.
Reference: Standard microprocessors and microcontrollers: 8085 interrupts
Question 4
Microprocessors & Microcontrollers8085 Interrupts

Which 8085 interrupt is non-vectored and requires external hardware to supply an instruction during interrupt acknowledge?

  • ATRAP
  • BRST 7.5
  • CRST 5.5
  • DINTR
Report an error
Correct Answer: D. INTR
Explanation: INTR is a general-purpose non-vectored interrupt; the external device must provide an instruction, commonly an RST opcode, during interrupt acknowledge.
Reference: Standard microprocessors and microcontrollers: 8085 interrupts
Question 5
Microprocessors & Microcontrollers8085 Interrupts

The 8085 instruction EI is used to?

  • AEnable maskable interrupts
  • BDisable all clock signals
  • CEnable only TRAP
  • DErase interrupt vectors
Report an error
Correct Answer: A. Enable maskable interrupts
Explanation: EI enables the maskable interrupt system after its specified activation behavior; TRAP is non-maskable.
Reference: Standard microprocessors and microcontrollers: 8085 interrupts
Question 6
Microprocessors & Microcontrollers8085 Interrupts

The 8085 instruction DI is used to?

  • ADisable maskable interrupts
  • BDisable TRAP permanently
  • CDecrease the accumulator
  • DDisable the address bus
Report an error
Correct Answer: A. Disable maskable interrupts
Explanation: DI disables maskable interrupts; it does not disable the non-maskable TRAP input.
Reference: Standard microprocessors and microcontrollers: 8085 interrupts