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8051 Interfacing MCQs

Practice 8051 Interfacing MCQs with four options, answers and explanations for focused Electronics & Telecommunication Engineering revision.

Question 1
Microprocessors & Microcontrollers8051 Interfacing

During external memory access in the 8051, Port 0 is multiplexed to carry?

  • ALow-order address and data
  • BOnly high-order address
  • COnly interrupt signals
  • DOnly serial data
Report an error
Correct Answer: A. Low-order address and data
Explanation: Port 0 serves as multiplexed AD0-AD7 for the low address byte and data bus during external-memory cycles.
Reference: Standard microprocessors and microcontrollers: 8051 interfacing
Question 2
Microprocessors & Microcontrollers8051 Interfacing

During external memory access, 8051 Port 2 commonly carries?

  • AHigh-order address byte
  • BOnly low-order data
  • CTimer overflow
  • DSerial receive data only
Report an error
Correct Answer: A. High-order address byte
Explanation: Port 2 supplies A8-A15 when the 8051 accesses external memory.
Reference: Standard microprocessors and microcontrollers: 8051 interfacing