G.H. Raisoni College of Engineering, Nagpur.
Department of Computer Science & Engineering
BE (VI Semester) CSE
Session 2009-2010
Subject : Microprocessor & Interfacing
Question Bank
UNIT I
Q1.What is a Microprocessor?
Q2.What is the difference between a Microprocessor and a CPU?
Q3. Define bit,byte,word and Instruction.
Q4. Discuss the function of ALU of 8085.
Q5. List four categories of 8085 Instructions that manipulate data.
Q6. What are the different Addressing Modes in 8085.
Q7.Why is Data Bus Bidirectional?
Q8. Specify four Control Signals commonly used by 8085 MPU.
Q9. What is the function of the Accumulator?
Q10. What are the various Registers of 8085?
Q11. Discuss Machine cycle and State.
Q12. What are the var8ious Status Flags provided in 8085?
Fill in the blanks:
Q13. Microprocessor 8085 is a ------------------ bit processor.
Q14. The Bus carries bits between Micropocessor and ------------------ .
Q15. Microprocessor has -------- number of pins.
Q16. Address bus of 8085 microprocessor is of -------- bits.
Q17. Data bus of 8085 microprocessor is of -------- bits.
Q18. An Instruction has two parts: Opcode and the -------------.
Q19. The method of specifying an Operand is called--------------.
Q20. Examples of 1-byte instruction -------------------------.
Q21. Examples of 2-byte instruction -------------------------.
Q22. Examples of 3-byte instruction -------------------------.
Q23. STA 2500 H takes ------------------ machine cycles.
Q24. LDA 2500 H takes ------------------ machine cycles.
Q25. MOV A,B takes ------------------ machine cycles.
Q26. LXI H 2600 H takes ------------------ machine cycles.
Q27. ADI ,09 takes ------------------ machine cycles.
Q28. IN ,02 takes ------------------ machine cycles.
Q29. There are ------------- addressing modes.
Q30. Discuss the function of HOLD,READY in 8085.
Q31.What is an Interrupt?
Q32. What are various Interrupt lines in 8085?
Q33. Differentiate between microprocessors and microcontroller in one line.
Q34. PUSH PSW means -------------Q35. POP PSW means ------------Q36. The function of ALE is ---------------Q37. Explain what is “Vectored Interrupt”.
Q38. Specify the crystal frequency required fo an 8085 system to operate at
1.1 MHz.
Q39. What is an assembler.
Q40. RAM of 1K* 8 means -------------------Q41. There are --------------- opcodes in 8085.
Q42. Examples of direct addressing mode is -----------------.
Q43. Examples of indirect addressing mode is -----------------.
Q44. Examples of register addressing mode is -----------------.
Q45. Examples of implicit addressing mode is -----------------.
Q47. Examples of control signals of 8085 ----------------------.
Q48. Data transfer instructions change the status of flags. State true or false.
Q49. CPM R means -----------------Q50.The CPU of a computer comprises of ------------------.
Q51. Operand is a term used to refer as --------------.
Q52. An 8-bit microprocessor signifies that it has -----------------.
Q53. The address bus width of 64 KB of memory is ----------------.
Q54. DCR register can be used to decrement the contents of ----------------.
Q55. A 3-byte instrction requires ------------- fetch cycles for its execution.
Q56. A 2- byte instrction requires ------------- fetch cycles for its execution.
Q57. A 1-byte instrction requires ------------- fetch cycles for its execution.
Q58. The term cycle stealing is used for ---------------.
Q59. The instruction MOV A,B belongs to ----------------- addressing mode.
Q60. The instruction MVI A,B belongs to ----------------- addressing mode.
Q61. The instruction LXI H, 2000H belongs to ----------------- addressing mode.
Q62. The instruction LDAX D belongs to ----------------- addressing mode.
Q63. What is memory word size required in an 8085 system?
Q64. Move the contents of register A to register B.
Q65. Move the contents of memory location 2000H to the accumulator directly.
Q66. List the sequence of events that occurs when 8085 MPU reads from
memory.
Q67. Load the HL pair with the address 2500H.
Q68. Move the data 09H to the B register.
Q69. Specify the two 8085 signals that are used to latch data in an output port.
Q70. Complement the contents of the carry flag.
Q71. Rotate the contents of the accumulator by one bit to the left through carry.
Q72. List conditional Call and Return instructions.
Q73. Explain the sequence of a program execution when a subroutine is called &
executed.
Q74. What is stack pointer and explain their uses?
Q75. What is Program counter and its uses?
Q76. The clock frequency required for 8085 is -----------.
Q77. Store the contents of accumulator in the memory location 2500H.
Q78. Increment the contents of memory location 2400H by 1.
Q79. What are the major differences between the 8080 and 8085
microprocessor?
Q80. Demonstrate the uses of instructions DAD,PCHL.
Q81. Decrement the contents of the register C by 2.
Q97. The instruction SPHL signifies -----------.
Q98. Explain the functions of Handshake signals.
Q99. Distinguish between Accumulator-Based and General Purpose Register –
Based
Microprocessors.
Q100. Write a program to add two numbers of 8-bit each.
Q101. Explain the need to demultiplex the bus AD7-Ado.
Q102. Write a program to count the number of 1’s in a 8-bit number.
Q103. Expain the functions of ALE and IO/M signals in 8085.
Q104. Show the register contents as each of the following instructions is being
executed
MVI C, FFH
LXI H, X X 70 H
LXI D, X X70 H
MOV M, C
LDAX D
HLT
Q105.Specify the contents of the accumulator and status of flags when following
instructions are executed.
MVI A, B7H
ORA A
Q106. Explain the direct addressing modes and indirect addressing modes of
8085 with example.
Q107. Explain the control and status signals of 8085
Q108. Explain the function of the 16-bit data transfer instruction LXI and of
instructon INX and DCX.
Q109. Explain stack and stack pointer.
Q110. Explain the difference between the bus cycle and the machine cycle.
Q111. Expain the RIM and SIM instruction.
Q112. Explain the following instruction:
a) DAA
b) LDA ,16 bit address
c) STA ,16 bit address
Q113. Explain how information is stored and retrieved from stack using PUSH
and POP
and the stack pointer.
Q114. Explain the following Subroutines:
a) Multiple calling
b) nesting
c) common ending
Q115. Compare similarities between PUSH/POP and CALL/RET instructions.
Q116. How many bytes the following instructions of 8085 need?
a) LDA
b) JNZ
c) RAL
d) MVI A
Q117. Explain the following instruction:
a) ADD M
b) CMA
c) CMP B
Q118. What are the functions of SID and SOD pins in 8085.
Q119.How are I/O devices addressed in 8085?
Q120. Write a program to exchange the contents of memory location 2000 H with
the
contents at memory location 2500 H.
Q121. Write a program to move the contents of memory location 2000H to
accumulator.
Increment these contents and place then in location 2001H.
Q122. Explain the function of READY signal of 8085 .
Q123. Give some examples of 32-bit and 64-bit microprocessors.
Q124. What are the trade-offs between software and hardware approaches in
implementing serial I/O?
Long Questions
Q125. Explain the architecture of microprocessors 8085.
Q126. Explain the pin diagram of 8085.
Q127. Explain the requirement of a program counter, stack pointer and status
flags in the
architecture of 8085 microprocessor.
Q128. Draw and explain the timing diagram of memory read cycle.
Q129. Draw and explain the timing diagram of memory write cycle with example.
Q130. Draw and explain the timing diagram of Opcode fetch cycle.
Q131.Explain the direct addressing modes and indirect addressing modes of
8085 with
example.
Q132. Assume that the accumulator contents data bytes 88 hand instruction
MOV C, A
4FH is fetched. List the steps decoding and executing the instruction.
Q133. Draw a timing diagram to interface a 4K ROM and a 2K RAM
consecutively with
microprocessor 8085, starting with ROM interfacing at address 0000 H. Explain.
Q134. Draw timing diagrams of
1) I/O read cycle
2) memory read cycle
3) Opcode fetch cycle
Q135. State addressing modes of the following modes with instruction with
justification
1) CMP B
2) JZ address
3) LDAX D
Q136. Write a program to arrange the following numbers in the descending
order-
23H,45H,09H,FFH,08H,27H.
Q137.Write a short note on the following:
a) machine cycle
b) instruction cycle
c) execute cycle
d) Vectored interrupt
Q138. Write a program for a Zero-to –Nine counter. Also draw the flowchart.
Q139. Define Addressing modes, Data formats with examples.
Q140. What you mean by the power of a Microprocessor? Mention the
Architectural
Parameters to distinguish between Microprocessors.
Q141. Describe a scheme to demultiplex the multiplexed AD0-AD7 bus of 8085
CPU.
Q142. Write a program to divide the two numbers .
Q143. Write notes on status flag?
Q144. Write an assembly language program to convert on array of ASCII code to
corresponding binary (hex) value. The ASCII array is stored starting from
4200H. The first element of the number of elements in the array.
Q145. How do the instructions of 8085 is classified based on their function and
word
length? Give an example?
UNIT II
Q1. What do you mean by memory mapping ? Explain.
Q2.What are different types of memory? Explain in detail.
Q3. Explain the memory mapped i/o addressing scheme.
Q4. Give the priority order of interrupts in 8085.
Q5. What are hardware interrupts? Discuss TRAP interrupt.
Q6. What are the control signals necessary in the memory-mapped I/O?
Q7. What are various schemes of data transfer from CPU/memory to I/O
devices?
Q8. TRAP is a maskable interrupt. State true or false.
Q9. What are Instructions EI,DI in the 8085 Interrupt process?
Q10. With the help of SIM instruction format, write the instruction to mask
RST 5.5.
Q11. List the eight steps to initiate and implement the 8085 interrupt.
Q12. What do you mean by polling.
Q13.Explain how to connect multiple interrupts with the INTR interrupt line.
Q14. Differentiate between maskable and non maskable interrupts.
Q15. How to use RIM and SIM instruction for 8085.
Q16. Discuss how memory chips and I/O devices are interfaced to a
microprocessor.
Q17. Explain five interrupt inputs of 8085 with priority.
Q18.What are Hardware and Software Interrupts? What is ISS?
Q19. Draw a diagram to interface a 6K ROM and a 2K RAM consecutively with
microprocessor 8085, starting with ROM interfacing at address 8000 H.
Q20. What is Interrupt ? Explain enabling, disabling and masking of interrupts
with
examples. How to transfer data using interrupts.
Q21. Explain how to use an RST instruction to implement a software breakpoint.
Q22. Explain an interrupt process and the difference between a maskable and
nonmaskable
interrupt by using examples.
Q23. Interface a 8K RAM consecutively with microprocessor 8085, starting with
ROM
interfacing at address 8000 H.
Q24. Explain the procedure of interfacing the temperature monitoring system with
8085.
.
UNIT III
Q 1. What are different operating modes of 8255?
Q 2. List the elements of 8255 programmable peripheral interface .
Q3. What is PPI ? Draw and explain the internal block diagram for 8255.
Q4. Explain the block diagram of the 8255 I/O section and timer.
Q5. Set up the 8255 I/O ports in the simple I/O and Bit Set/Reset(BSR) mode.
Q6. Give the control word format of timer?
Q7. Name the two modes of operation of DMA controller?
Q8. Explain the process of the Direct Memory Access(DMA) and the functions of
various elements of the 8237.
Q9. Explain how the 8237 DMA controller transfers 64K bytes of data per
channel with
eight address lines.
Q10. Specify handshaking signals and their functions if port A of 8255 is set-up
as input
port in mode 1.
Q11. Discuss in detail about the operation of timer along with its various modes.
Q12. Draw the Block diagram of DMA controller and explain its operations.
UNIT IV
Q1. Explain block diagram of the 8279 Keyboard/Display interface and its
operations.
Q2. Write instructions to initialize the 8279 in a given mode.
Q3. Explain the block diagram of the 8279 Keyboard/Display interface and its
operations.
Q4. What is the use of Keyboard and display controller?
Q5. Draw the block diagram of programmable interrupt controller and explain its
operations.
Q6. What is stepper motor ? Explain its operation.
Q7. Explain how to interface stepper motor with microprocessor 8085 .
UNIT V
Q1. Differentiate microprocessor and microcontrollers.
Q 2. Differentiate RRA and RRC A instructions of 8051.
Q 3. Give the format of PSW register of 8051.
Q 4. What is the jump range in 8051?
Q 5. List the features of 8051.
Q 6. Define a Microcontroller.
Q 7. What are the special function registers in 8051?
Q 8. What is the use of PCON register?
Q 9. State the function of RS0 and RS1 bits of PSW?
Q 10. Give the interrupt priorities of 8051.
Q 11. List the addressing modes of 8051.
Q 12. What is the use of TCON register?
Q 13. What is the RAM size of 8051?
Q 14 Describe the architecture of 8051 with a neat diagram.
Q 15. Explain the interrupt structure, SFR and timers of 8051.
Q 16. List out the salient features of 8051 Microcontroller.
Q 17. Explain the following instructions of 8051 with examples.
i. CJNE destination, source, label
ii. MUL AB
iii. RRL A
iv. SWAP A
v. SETB P2.0
Q 18. Discuss in detail stepper motor interfacing with 8051.
UNIT VI
Q1. What is the use of USART and UART ?
Q2. Compare serial and parallel communication.
Q3. Draw the Block diagram and explain the operations of 8251 serial
communication
interface.
Q3. Compare synchronous and asynchronous mode of data transfer.
Q4.Explain the RS-232C serial I/O standard and compare it with RS-422A
standard.
Q5. Explain terms synchronous, baud rate, parity , half and full duplex
transmission.
Q6. Explain how data bits are transmitted in the asynchronous format, and
calculate the
delay required between two successive bits for a given baud.
Q7. Explain the block diagram and the functions of each block of the 8251
USART
(Programmable Communication Interface).