MPandMC Quiz 2025

In a microprocessor system, the data bus is primarily used to

• Carry the memory address

• Carry control signals

• Transfer data between CPU and memory/peripherals

• Decode instructions

What is the function of the ALE (Address Latch Enable) pin in 8085?

• To enable data flow

• To latch the lower byte of the address

• To enable interrupts

• To start program execution

Which of the following is a logical instruction in 8085?

• ADD B

• CMP C

• MOV A, B

• INR D

What does the following 8085 assembly code do?

MVI A, 05H

MVI B, 03H

ADD B

• Multiplies 05 and 03

• Adds 05 and 03 and stores in B

• Adds 05 and 03 and stores in A

• Adds 05 and 03 and stores in memory

Which of the following instructions uses Register Indirect Addressing Mode?

• MVI A, 0AH

• MOV A, M

• LDA 2050H

• STA 3050H

What is the function of the MN/MX̅ pin in 8086 microprocessor?

• Enables memory access

• Selects minimum or maximum mode

• Interrupt acknowledge

• Bus high enable

Which of the following interrupt types has the highest priority in 8086?

• Type 1 – Single Step

• Type 2 – Non-maskable interrupt

• Type 3 – Breakpoint

• Type 4 – Overflow

In 8086, which unit is responsible for fetching the instructions from memory?

• Execution Unit

• Control Unit

• Bus Interface Unit

• Arithmetic Logic Unit

What is the purpose of the DB directive in assembly language?

• Defines a byte

• Declares a buffer

• Deletes a byte from memory

• Debugs a byte

The function of the READY pin in 8086 is to

• Indicate the end of an instruction

• Enable external interrupts

• Synchronize slower peripherals with CPU

• Reset the CPU