Sri Sai Ranganathan Engineering College

(An Autonomous Institution)

Approved by AICTE, New Delhi and Affiliated to Anna University,
Chennai
Rec Kalvi Nagar, Thondamuthur via, Viraliyur post, Coimbatore-
641109
Department of Electrical and Electronics Engineering
IV Semester
B.E – EEE
EE3404 MICROPROCESSOR AND MICROCONTROLLER
QUESTION BANK
(Regulations 2024)
UNIT I – INTRODUCTION TO 8085 ARCHITECTURE
Functional block diagram – Memory interfacing–I/O ports and data transfer concepts – Timing
Diagram – Interrupt structure.

PART – A

Q. No. Question M CO# KL

1 List two major differences between INTR and the other hardware
interrupts. (ND-2019) 2 CO1 K1
2 Does the 8085 support externally initiated operations. If yes, how? (ND- 2 CO1 K1
2019)
3 Calculate the number of memory chips needed to design 8K-byte 2 CO1 K3
memory if the memory chip size is 1024 x 1. (ND-2020)
4 Why is crystal a preferred clock source? (ND-2020) 2 CO1 K1
5 What are the functions of an accumulator? (ND-2021) 2 CO1 K1
6 List the 16-bit registers of the 8085 microprocessors. (ND-2021) 2 CO1 K2
7 Write an example for each instruction. (AM-2022) 2 CO1 K1
8 What are the conditions under which a LOOPZ instruction exits looping? 2 CO1 K1
(AM-2022)
9 Mention the significance of the HOLD signal in the 8085 2 CO1 K1
microprocessors. (ND-2023)
10 Specify the Status and Control signal values for different machine cycles 2 CO1 K1
in 8085 microprocessors? (ND-2023)
11 Expand (a) PC (b) SP (c) ALU (d) ALE (AM-2023) 2 CO1 K1

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12 Find the maximum external memory that shall be interfaced with 8085, 2 CO1 K1
which has 16-bit address lines (AM-2023)
13 How many operands does each of the following instructions of 8086 2 CO1 K1
have? (a) ADD (b) ADC (c) INC (d) ROR
PART- B
1 With a functional block diagram, briefly discuss the architecture of the 13 CO1 K2
8085 microprocessors. (ND-2019)
2 Draw the timing diagram of the instruction MVI B, 45. Assume the 13 CO1 K2
memory address of the opcode and the data is 2000H and 2001 H
respectively. (ND-2019)
3 List the steps to he performed by the Micro Processing Unit (MPU) 13 CO1 K2
during the communication process with peripheral devices. Also, explain
the functions of address bus, data bus and control bus in the
communication process between the MPU and peripheral devices. (ND-
2020)
4 Show how the MPU reads an instruction from a memory location. (ND- 13 CO1 K3
2020)
5 Show the internal architecture of the 8085 microprocessors with neat 13 CO1 K3
functional block diagram and explain the functions of each internal unit
in decoding and executing an instruction (ND-2020)
6 With the help of a neat diagram, explain the architecture of the 8085 13 CO1 K2
microprocessor in detail. (ND-2021)
7 Draw the microprocessor bus timing for the instruction STA 2022 H and 13 CO1 K2
explain it. (ND-2021)
8 With a neat sketch, briefly explain the interrupt structure of 8085 13 CO1 K2
microprocessor. (ND-2023)
9 Draw and explain the timing diagram of CALL instruction in 8085 13 CO1 K2
microprocessor. (ND-2023)
10 Explain the software and hardware interrupts available in 8085 along 13 CO1 K2
with their vector addresses. (AM-2023)
11 Draw and explain the timing diagram of (1) Memory read machine cycle 13 CO1 K2
and (ii) Memory write cycle of 8085. (AM-2023)

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 12 The instruction code 01001111 (4FH) is stored in memory location 13 CO1 K3
5005H. Illustrate the data flow with an appropriate sketch and list the
sequence of events when the instruction code is fetched by the 8085
MPU (AM-2024)
UNIT-II 8085 INSTRUCTION SET AND PROGRAMMING
Instruction format and addressing modes – Assembly language format – Data transfer, data
manipulation & control instructions – Programming: Loop structure with counting & Indexing -
Look up table - Subroutine instructions, stack.
PART-A
1 Illustrate the changes made to the content of registers during the
execution of the instruction LXI B. 4000 Н. (ND-2019) 2 CO2 K3
2 State the advantages of subroutine (ND-2019) 2 CO2 K1
3 Define a subroutine (ND-2020) 2 CO2 K1
4 If the program counter is always one count ahead of the memory location 2 CO2 K2
from which the machine code is being fetched, how does the
microprocessor change the sequence of program execution with a jump
instruction? (ND-2020)
5 What is an operand? (ND-2021) 2 CO2 K1
6 Write an assembly language program to add two 8 bit numbers stored at 2 CO2 K1
address 2020 and address 2021 in 8085 microprocessor. The starting
address of the program is taken as 2000 (ND-2021)
7 Using 8086 and 8087, draw a coprocessor configuration with relevant 2 CO2 K1
signals. (AM-2022)
8 Draw the diagram for address/data demultiplexing of 8086? (AM-2022) 2 CO2 K1
9 Write the functionality of the DAA instruction with an appropriate 2 CO2 K1
example? (ND-2023)
10 Illustrate the steps necessary to add ten bytes of data stored in memory 2 CO2 K3
locations starting at a given location, and display the sum? (ND-2023)
11 Why subroutine is called so? (AM-2023) 2 CO2 K1
12 State any two applications of lookup table. (AM-2023) 2 CO2 K1
13 What is the functionality of the DAA instruction? (AM-2024) 2 CO2 K1
14 Write the differences between a memory-mapped 10 and 10 mapped 10. 2 CO2 K1
(AM-2024)
PART-B
1 Differentiate RAL and RLC instructions. (ND-2019) 6 CO2 K2

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 Write an assembly language program for the 8085 microprocessor to 7 CO2 K2
2
count even numbers in a series of 10 numbers. (ND-2019)
3 Briefly describe the stack pointer register.(ND-2019) 6 CO2 K2
Briefly discuss the different types of addressing modes supported by the 7 CO2 K2
4
8085 microprocessors with examples. (ND-2019)
With suitable examples, explain the addressing modes of 8085. (ND- 13 CO2 K2
5
2021), (AM-2023)
Illustrate the contents of the stack memory and registers when PUSH and 13 CO2 K3
6 POP instructions are executed, and explain how memory pointers are
exchanged. (ND-2023)
Write an assembly language program to perform a bubble sorting 13 CO2 K2
7
operation. (ND-2023)
State the data manipulation instructions for the 8051 microprocessor and 13 CO2 K2
8
mention their functions. (AM-2023)
Define addressing modes. Also, comment on the addressing modes 13 CO2 K2
9
supported in 8085 microprocessors with suitable examples. (AM-2024)
Write a subroutine to set the Zero flag and check whether the instruction 13 CO2 K2
10
JZ (Jump on Zero) functions. (AM-2024)
Write an assembly language program to swap two 8-bit numbers using 13 CO2 K2
direct addressing mode, where the first 8-bit number is stored at 3000H
11
and the second 8-bit number is stored at 1001H memory address. (ND-
2020)
Explain the operation of instructions related to the rotation of the 13 CO2 K2
12 accumulator bits with an example. Also state any two applications of the
rotate instruction (ND-2020)
Explain the function of the following instructions with one example. HL 13 CO2 K2
13 (iii) LDAX (iv) CMP (v) STA (vi) SHLD. (ND-2021)

UNIT III INTERFACING BASICS AND ICS

Study of Architecture and programming of ICs: 8255 PPI, 8259PIC, 8251USART, 8279 Keyboard
display controller and 8254 Timer/Counter – Interfacing with 8085 -A/D and D/A converter
interfacing.
PART-A
Can a single bit of a port be accessed in 8051? If yes, how? Give an
1
example. (ND-2019). 2 CO3 K2

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2 What are the flags supported by 8051 microcontrollers? (ND-2019) 2 CO3 K1
Show the internal data memory organization of the 8051 microcontrollers? 2 CO3 K3
3
(ND-2020)
How does the CPU know where to return to after executing the RET 2 CO3 K1
4
instruction? (ND-2020)
List the alternate functions of port 3 in the 8051 microcontrollers. (ND- 2 CO3 K1
5
2021)
What is the significance of the modes of operation of the PPI 8255? (AM- 2 CO3 K1
6
2022)
What is the sequence of actions that occur in an interrupt acknowledge 2 CO3 K1
7
cycle? (AM-2022)
8 Mention the prominent features of 8255. (ND-2023) 2 CO3 K1
What are the two modes of 7-segment display operations in 8279? (ND- 2 CO3 K1
9
2023)
10 Discuss the capabilities of the 8251 USART chip. (AM-2023) 2 CO3 K1
Name the registers used to program and control the operation of the IC 2 CO3 K1
11
8259PIC. (AM-2023)
What is the significance of the modem control signals in 82517? (AM- 2 CO3 K1
12
2024)
Show how the flag register is affected by the following instruction 2 CO3 K3
13 MOV A,#0F5H
ADD A,#0AH (ND-2021)
PART-B
With a functional block diagram, briefly discuss the architecture of the 7 CO3 K2
1
8051 microcontrollers (ND-2019), (ND-2020)
Summarize the similarities and differences between 8085 and 8051. (ND- 6 CO3 K2
2
2019)
Discuss in detail the internal data memory organization of the 8051 7 CO3 K2
3
microcontrollers. (ND-2019)
4 Distinguish between a microprocessor and a microcontroller. (ND-2019) 6 CO3 K2
List the categories under which the instructions in the instruction set of 13 CO3 K2
5 the 8051 microcontrollers are grouped. Explain the operation of any two
instructions in each group. (ND-2020)
Discuss in detail about memory organization and the expansion of 13 CO3 K2
6
memory in 8051 with a neat diagram (ND-2021)

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 Explain the interrupt structure of the 8051 microcontroller and also 13 CO3 K2
7
explain how interrupts are prioritized. (ND-2021)
With a neat circuit diagram/functional block diagram, interface an analog 13 CO3 K2
sensor with 8085 microprocessors. Also, write an assembly language
8
program to read, convert the sensor value, and save the result in 8000H.
(ND-2023)
Briefly explain the different modes of operation in the 8254 IC. Support 13 CO3 K2
9
the answer with appropriate timing diagrams (ND-2023
With a neat diagram, explain the architecture and interfacing of the 8255 13 CO3 K2
10
PPL. (AM-2023)
Draw the internal block diagram of the 8279-keyboard display controller 13 CO3 K2
11
and explain its features. (AM-2023)
Discuss in detail the various modes and operation of the programmable 13 CO3 K2
12
timer 8254 when it is interfaced with the 8085 processor. (AM-2024)
Discuss in detail the various modes of operation of the 8279 with various 13 CO3 K2
13
functional blocks and the control word registers. (AM-2024)
UNIT - IV INTRODUCTION TO 8051 MICROCONTROLLER
Functional block diagram - Instruction format and addressing modes – Interrupt structure – Timer
– I/O ports – Serial communication, Simple programming –keyboard and display interface –
Temperature control system –stepper motor control - Usage of IDE for assembly language
programming.
PART-A
1 Differentiate programmed I/O and interrupt driven I/O. (ND-2019) 2 CO4 K2
2 Why an interface is needed in between CPU and input-output devices? 2 CO4 K1
(ND-2019)
3 Show the control word format for 8255 I/O mode ? (ND-2020) 2 CO4 K3
4 Compare automatic rotation and specific rotation priority modes of 8259. 2 CO4 K2
(ND-2020)
5 Specify the bit of a control word for 8255, which differentiates between the 2 CO4 K1
I/O mode and the BSR mode. (ND-2021)
6 List the various modes of 8254 Timer. (ND-2021) 2 CO4 K1
7 What is the difference between the LJMP and SJMP instructions of 8051? 2 CO4 K1
(AM-2022)
8 What is the use of the NOP instruction? Show its use in an example. (AM- 2 CO4 K1
2022)

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 9 Define the contents in the program status word. (ND-2023) 2 CO4 K1
10 State the methodology of RAM allocation in 8051 microcontroller. (ND- 2 CO4 K1
2023)
11 Mention the role of the stack pointer in using the stack. (AM-2023) 2 CO4 K1
12 Define IDE. (AM-2023) 2 CO4 K1
13 Differentiate 8085 microprocessor and 8051 microcontroller. (AM-2024) 2 CO4 K2
PART-B
Sketch the block diagram of the 8279 Keyboard Display Interface and 13 CO4 K2
1
explain the functions of the Keyboard and Display sections. (ND-2020)
Sketch the block diagram of the 8254 Programmable Interval Timer and 13 CO4 K2
2 explain the functions of each internal block. Also, list the operating
modes of the 8254 timers. (ND-2020)
3 Describe the operating modes and control words of 8255. (ND-2019) 13 CO4 K2
With a functional block diagram, briefly discuss the architecture of the 13 CO4 K2
4
8259 programmable interrupt controllers. (ND-2019)
Draw and explain block diagram of 8259A programmable interrupt 13 CO4 K2
5
controller in detail. Explain control word definition of the same. (ND-2021)
With neat block diagram, explain the description and function of 8254.
6
(ND-2021) 13 CO4 K2
With a neat circuit diagram and assembly language program, briefly
7 explain the process of interfacing a unipolar stepper motor with 8051 13 CO4 K2
microcontrollers in 4-step sequence/bi- phase mode. (ND-2023)
Explain the various operating modes of 8051 timer and special function 13 CO4 K2
8
registers associated with timer/counter. (AM-2023)
Explain the structure of port 0 and port 3 of 8051 microcontroller. (AM- 13 CO4 K2
9
2023)
Briefly explain the methodology of interfacing and configuring an 13 CO4 K2
10
external memory with 8051 microcontrollers. (AM-2024)
Discuss in detail about timer mode and control operations of 8051 13 CO4 K2
11
microcontrollers with the relevant special function registers. (AM-2024)
UNIT V INTRODUCTION TO RISC BASED ARCHITECTURE
PIC16 /18 architecture, Memory organization – Addressing modes – Instruction set - Programming
techniques – Timers – I/O ports – Interrupt programming.
PART-A

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 Write a program to load the accumulator with the value 82H and 2 K1
1 CO5
complement the accumulator 700 times. (ND-2019)
2 List any four applications of 8051 to automation systems. (ND-2019) 2 CO5 K1
Assume that a stepper motor is running in full-step mode with step angle = 2 CO5 K1
3
1.8 deg. How many steps are required to make 2 full rotations. ( ND-2021)
If CY=1, A95H and B4FH prior to the execution of "SUBB A, B", what 2 CO5 K2
4
will be the contents of A after the subtraction? (ND-2020)
5 What is the role of SBUF in serial communication (in 8051) ? (AM-2022) 2 CO5 K1
Name the four porta of 8051 and state the differences between them. (AM- 2 CO5 K1
6
2022)
Comment on the organization of program memory and data memory in PIC 2 CO5 K1
7
16 series microcontroller? (ND-2023)
Write the functionality of INCFSZ f, d instruction in PIC 16 series 2 CO5 K1
8
microcontroller. (ND-2023)
9 Compare CISC with RISC. (AM-2023) 2 CO5 K2
10 List any four special features of PIC controller. (AM-2023) 2 CO5 K1
11 What is brownout reset? (AM-2024) 2 CO5 K1
12 Mention the functionality of DECFSZ f, d instruction. (AM-2024) 2 CO5 K1
PART-B
Show how to interface a Liquid Crystal Display (LCD) to an 8051 13 CO5 K3
1
microcontroller. (ND-2020)
Write a program using 8051 instructions to send commands and data to
2
LCDs with a time delay. (ND-2020) 13 CO5 K2
Show how to interface a stepper motor to 8051 microcontrollers. Also, 7+
3 write an assembly language program to demonstrate control of the 6 CO5 K3
direction and speed of the stepper motor rotation. (ND-2019)
Show how to interface a servo motor to an 8051 microcontroller. Also, 13 CO5 K3
4 explain the working principle to control a servo motor with angle rotations
(ND-2019)
Write in detail about the interfacing of the LCD with the 8051 13 CO5 K2
5
microcontrollers (ND-2021)
Describe the basic operation of a stepper motor and also discuss how to 13 CO5 K2
6
interface a stepper motor with 8085 microprocessors. (ND-2021)
With a neat sketch, describe the features and architecture of the PIC16F877 13 CO5 K2
7
microcontroller. (ND-2023)

Page 8 of 9
 With a neat sketch, detail the interrupt structure supported in the 13 CO5 K2
8
PIC16F877 microcontroller. (ND-2023)
With a neat sketch, details about the different functional blocks available 6 CO5 K2
9
in the PIC16 series of microcontrollers. (AM-2024)
Briefly explain the process of configuring and programming the external 13 CO5 K2
10 interrupts in the PIC16 Series MCU. Illustrate it with a real-time example.
(AM-2024)
Draw the architecture and list the major functional elements of the PIC 13 CO5 K2
11
microcontroller. (AM-2023)
Mention the instructions of the PIC microcontroller and their function? 13 CO5 K2
12
(AM-2023)

M – Marks
CO# - Course Outcome Number
KL – Knowledge Level (K1, K2, K3, K4, K5, K6)

STAFF INCHARGE HOD IQAC

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