Microcontrollers 80 Marks Sample Question Paper

1. Sample Question Paper-I
Course Name : Electronics Engineering Group
Course Code : ET/EN/EX/EJ/IE/IS/IC/DE/EV/MU/IU/ED/EI 9121
Semester : Fifth for ET/EN/EX/EJ/IE/IS/IC/DE/EV/MU and Seventh for IU/ED/EI
Subject : Microcontrollers
Marks : 80 Time: 03 Hrs
Instructions:
1. All questions are compulsory.
2. Illustrate your answers with neat sketches wherever necessary.
3. Figures to the right indicate full marks.
4. Assume suitable data if necessary.
5. Preferably, write the answers in sequential order.
Q.1. Attempt any FOUR of the following. 16 Marks
a) Name data transfer techniques used in microprocessor.
b) Draw & label block diagram of IC 8155.
c) List eight commercial microcontroller devices used for industrial purpose.
d) State the functions of AC flag & parity flag used in microcontroller 8051.
e) Draw internal RAM structure of 8051.
f) Describe the function of following instructions of 8051
i) JZ radd ii) DAA
Q.2. Attempt any THREE of the following. 12 Marks
a) Explain power saving options of 8051 microcontroller.
b) Describe serial control register (SCON) of 8051.
c) Interface external program memory with 8051 & explain how the data is transferred.
d) Give the features of IC 8355.
Q.3. Attempt any THREE of the following. 12 Marks
a) Give the alternate functions of port 3 pins of 8051 microcontroller.
b) Explain a Boolean processor of microcontroller 8051with two examples.
c) Draw the format of timer control register (TCON) and describe it.
d) Compare between microprocessor & microcontroller based on no. of instructions
used, registers, memory and applications.

2. Q.4. Attempt any TWO of the following. 16 Marks
a) Draw the complete interfacing diagram of 8085 with DAC (using 8255) & write a
program to generate triangular wave.
b) Draw architecture of 8051 microcontroller and describe functions of DPTR, PC &
stack pointer.
c) Define addressing mode of 8051. Describe addressing modes with example.
Q.5. Attempt any TWO of the following. 12 Marks
a) Describe interrupts used in 8051. Give their priority & addresses.
b) State & explain tools needed for testing and development of microcontroller boards?
c) Interface a stepper motor to 8085 using 8255 & describe it.
Q.6. Attempt any TWO of the following. 12 Marks
a) Describe the three operating modes of IC 8255.
b) Write a program to multiply the unsigned number in register R3 by the unsigned
number on port 2 and put the result in external RAM locations 10H(MSB) &
11H(LSB).
c) Write a program to generate 2KHz square wave on pin P1.0 of port 1 of 8051
microcontroller. (Use Interrupt)