Microprocessor Interview Questions - 4

1. What is the size of flag register of 8086 processor?


16-bit.

2. How many pin IC 8086 is?


40 pin dual in-line package.

3. What is the Maximum clock frequency of 8086?


5 Mhz is the Maximum clock frequency of 8086.

4. What is meant by instruction cycle?


An instruction cycle also known as fetch-and-execute cycle and fetch-decode-execute cycle, is the time period during which a computer reads and processes a machine language instruction from its memory.

5. What is Von Neumann architecture?


The Von Neumann architecture is a computer design model that uses a processing unit and a single separate storage structure to hold both instructions and data. The instruction/data is read from storage and executed by the processing unit. It is also known as "stored-program computer".

6. What is the main difference between 8086 and 8085?


8086 is 16-bit microprocessor, where as 8085 is a 8-bit microprocessor.

7. What does EAX mean?


With the advent of the 32-bit 80386 processor, the 16-bit general-purpose registers, base registers, index registers, instruction pointer, and FLAGS register, but not the segment registers, were expanded to 32 bits. This is represented by prefixing an "E" (for Extended) to the register opcodes, thus the expanded AX became EAX.(Similarly BX became EBX, SI became ESI and so on).

8. What type of instructions are available in instruction set of 8086?


  • Data Instructions
  • Arithmetic Instructions
  • Logic Instructions
  • Control Instructions
  • Other - setting/clearing flag bits, stack operations, software interrupts, etc.


9. How is Stack Pointer affected when a PUSH and POP operations are performed?


When PUSH operation is performed the SP value is decreased by 2. When POP operation is performed the SP value is increased by 2.

10. What are SIM and RIM instructions?


SIM - Set Interrupt Mask, is used to mask the hardware interrupts. RIM - Read Interrupt Mask, is used to check whether the interrupt is Masked or not.

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