Microprocessor 8085 Question Bank - 02

Architecture and operation:

1.  Give a general block diagram of a microprocessor based system. Explain     

     briefly the various blocks of the system. Give some examples of the types of 

     devices used for each block.

2.  What is a microprocessor? Sketch and explain the various pins of 8085.

3.  Sketch and explain the signal diagram of 8085.

4.  Explain the operation of 8085 signals: READY, S1 & S0, HOLD & HLDA and  

     ALE.

5.  Explain the architecture of 8085 with the help of its internal block schematic.

6.  Write the flag register and explain each of the flags with an example.

7.  Mention the list of registers of 8085 that are accessible to the programmer. 

8.  Explain what each of these registers is generally used for.

9.  What should be the starting address of ROM for an 8085 microcomputer? 

     Substantiate your answer.

10. Explain the purpose of the following signals of 8085: AD0-AD7, /RESET IN, 

      RESET OUT, and RST 7.5.

11. Explain with schematic diagram how separate address, data signals can be 

      generated from 8085 common address-data lines.

12. List the control and status signals in 8085. Explain their functions.

13. What are RAM’s and ROM’s? Why should both of these be used in an 8085 

      system? 

14. Explain the functions of following 8085 registers in Intel 8085: HL, STACK 

      POINTER, and FLAG REGISTER.  

15. Specify the contents of the registers and the flag status as the following   

      instructions are executed.

            MVI A, 00H

            MVI B, F8H

            MOV C, A

            MOV D, B

            HLT

16. Write instructions to load the hexadecimal number 65H in register C and    

     92H in accumulator A, Display the number 65H at PORT0 and 92H at PORT1.

17. Draw and explain the block diagram of a microprocessor 8085.  

18. Why the lower order address bus is multiplexed with data bus? How they 

      will be de-multiplexed?

19. Differentiate between maskable and non-maskable interrupts. 

20. Mention the functions of the following pins of 8085: ALE, CLK OUT, RESET 

     OUT, RESET IN. 

21. Explain in detail the following instructions:-  

       (i) ADC    (ii) LHLD     (iii) RLC    (iv) DI

22. What are the various addressing modes available in 8085? Explain with   

      examples.

23. Compare the memory mapped I/O with peripheral mapped I/O.

24. Explain data transfer techniques.

25. Mention the functions of RIM and SIM.