VARDHAMAN COLLEGE OF ENGINEERING
(AUTONOMOUS)
B. Tech VI Semester Regular Examinations, May 2018
(Regulations: VCE-R15)
MICROPROCESSORS AND MICROCONTROLLERS
(Electrical and Electronics Engineering)
Date: 14 May, 2018 FN Time: 3 hours Max Marks: 75
Answer ONE question from each Unit
All Questions Carry Equal Marks
Unit I
1. Explain the architecture of 8086 microprocessor with a neat block diagram. 10M
Explain memory segmentation. What are advantages of segmented memory scheme?
5M
2. With a neat block diagram, explain the maximum mode operation of 8086
microprocessor.
8M
Mention the addressing mode and determine the physical address resulting from the
following instructions:
MOV
MOV
MOV DI
MOV
BP 7000H, SI 0350H, SS 8000H, BX 4FFFH, DS 2000H and DI 6A00H.
7M
Unit II
3. Explain the addressing and address decoding logic when a memory is connected to 8086.
7M
Analyze the following 8086 ALP and determine the outcome of executing it:
MOV AL, 26H
MOV BL,AL
AND AL,F0H
MOV CL,4
ROR AL,CL
ADD AL,30H
MOV AH,0EH
INT 10H
MOV AL,BL
AND AL,0FH
ADD AL,30H
INT 10H
INT 20H
8M
4. Discuss about the stack operations performed when a CALL and RET is executed. 8M
Write an 8086 ALP to find the highest of five numbers and write the result in DL.
7M
Unit III
5. Suggest a scheme to connect an 8-bit DAC to 8086. Present your answer in the form of
circuit diagram and appropriate explanations.
7M
Using a block diagram, explain the functionality of 8259 peripheral interrupt controller.
8M
6. Discuss the operation of 8255 PPI in mode-2 (bi-directional handshake). 7M
In an abstract manner, explain DOS and BIOS interrupts.
8M
Unit IV
7. With a neat diagram, explain the internal architecture of 8051 microcontroller. 10M
Write an ALP to add the contents of RAM location 60H, 61H and 62H. Store the result in
RAM locations 41H and 40H (LSB).
5M
Cont…2

8.

Interface 16 K EPROM and 8K RAM to 8051 Microcontroller. Write a neat diagram to show the interfacing along with memory map.
7M

Write an ALP using timer in MODE 1 to generate a square wave with an ON time of 3 ms and an OFF time of 10 ms. Assume an XTAL of 22MHz.
8M
Unit V
9.

What is the difference between asynchronous and synchronous communication? Explain.
5M

Draw the interfacing diagram of a 4x4 matrix keyboard connected to port-1 and port-2 of 8051. Also, write an algorithm to determine the key pressed.
10M
10.
Design an 8051 based system to control the speed of a permanent magnet dc motor. Provide your answers with an algorithm, program and an abstract circuit diagram (without part number or component values).