Microprocessor Two Marks Qbank

XIT 404 MICROPROCESSOR & MICROCONTROLLER TWO MARKS QUESTION BANK

1. What is the need to Demultiplex the bus AD7-AD0? 2. If the Clock frequency is 5MHz, how much time is required to execute an instruction of 18 T-states? 3. Write the features of 8085. 4. List the Internal registers in 8085. 5.

What operation can be performed by using the instruction CMP B? Specify the status of Z and CY flags.

6. What is the necessity of HOLD and HLDA pins in DMA data transfer operation ? 7. Write the Operation Carried out when 8085 executes DAA instruction. 8. Write instructions to

9.

(i)

clear the accumulator

(ii)

Decrement the accumulator

If the 8085 has fetched the machine code located at the memory location 205F H, Specify the contents of the Program Counter

10. Write the Operation Carried out when 8085 executes DAA instruction. 11. List the signals related to DMA operation in 8085. 12. Write instructions to (i)

clear the accumulator

(ii)

Decrement the accumulator

13. Define Program counter. 14. What is the use of ALE signal? 15. Define Direct Addressing Mode with an example.

MS.R.RAJAKUMARI AP/IT, PMU, VALLAM

16. Assume that memory location 2075H has a data byte 47H. Specify the contents of the address bus A15-A8 and the multiplexed bus AD7-AD0 when the MPU asserts the RD signal. 17. Define Implied Addressing mode with an example. 18. Mention any four Logical instructions of 8085. 19. Define Machine Cycle. 20. If the 8085 adds 87H and 79H,Specify the contents of accumulator and the status of the S,Z and CY flags. 21. Define Instruction cycle. 22. Give the significance of RIM instruction available in 8085 processor. 23. Define SP. 24. Specify the function of HOLD and HLDA Signals in 8085. 25. Give the significance of SIM instruction available in 8085 processor. 26. Write any two features of 8086 Microprocessor. 27. What are Assembler Directives? Give 2 examples. 28. Let the accumulator content is 9AH and CY=1,what will be the content of CY after RRC instruction is executed. 29. What is the addressing mode of the following 8086 instruction. JMP[3001H] MOV AX,55H[BX][SI] 30. What do you mean by Pipelining? 31. Give the significance of TRAP flag. 32. What is the difference between Hardware Interrupt & Software Interrupt? 33. How the Physical address is calculated in 8086 processor?

MS.R.RAJAKUMARI AP/IT, PMU, VALLAM

34. Write the functions of the following signals. (i)

MN/MX

(ii)

RQ/ GT

35. How will you enter the single step mode of 8086? 36. What is Interrupt vector table? 37. What is the advantage of using Pipelining in 8086 processor? 38. Give the significance of Direction flag. 39. Draw the bit pattern for flag register of 8086. 40. Draw the register organization of 8086? 41. Write the Operation Carried out when 8086 executes AAA instruction. 42. What are the sources of interrupts in 8086? 43. List any two shift Instructions of 8086. 44. Define the Assembler Directive DB. 45. Define Assembler. 46. Give the significance of Overflow flag. 47. List any four Assembler Directives. 48. What is the function of Instruction Queue? 49. What are the advantages of using Memory Segmentation? 50. What is the function of SI and DI registers in String related operations?

ALL THE BEST

MS.R.RAJAKUMARI AP/IT, PMU, VALLAM