Enrolment No.
/Seat No_______________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE- SEMESTER–IV (NEW) EXAMINATION – WINTER 2024
Subject Code: 3141710 Date: 27-11-2024
Subject Name: Microprocessor and Interfacing
Time: 02:30 PM TO 05:00 PM Total Marks: 70
Instructions:
1. Attempt all questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.
4. Simple and non-programmable scientific calculators are allowed.
MARKS
Q.1 (a) Distinguish between assembly language and high level languages 03
(b) Explain functioning of following pins of 8085. 04
(i) ALE (ii) READY (iii) INTR (iv) HOLD
(c) What do we mean by Addressing Modes? Explain, giving suitable example, 07
all the addressing modes supported by 8085.
Q.2 (a) Draw circuit diagram to generate memory and I/O read write control signal 03
by 8085.
(b) Explain the operation of 8085 pin signals: READY, AD0-AD7, HOLD and 04
S0 & S1
(c) Draw and Explain the functional block diagram of internal architecture of 07
8085 and explain its working.
OR
(c) Explain flag register of 8085 and explain each flag with proper example in 07
detail.
Q.3 (a) Explain following instructions of 8085. 03
(i) LDA (ii) RAL (iii) DAA
(b) What is stack and stack pointer? Explain working of PUSH and POP 04
instructions with suitable example
(c) Draw and explain timing diagram of instruction MOV C,A stored in location 07
2005H,and its opcode is 4F H.
OR
Q.3 (a) Compare absolute decoding v/s partial decoding. 03
(b) Data block of ten data bytes is stored in memory starting from locations 04
2000H.Write a program to count even numbers in this data block. Store the
result in memory location 3000H
(c) Design an Interfacing circuit to connect 4k×8 EPROM with starting address 07
from 0000H and 2k×8 RAM starting address 2000H onwards. Write address
range for both the memory chips showing address decoding logic.
Q.4 (a) Define vector interrupt. List of total vector interrupts of 8085. 03
(b) Write the steps of responding to interrupt by 8085 microprocessor in detail. 04
(c) Explain the function of RIM and SIM instructions in 8085 with description 07
of each bit.
OR
Q.4 (a) Write the differences between software interrupts and hardware interrupts. 03
(b) What is key bouncing? How can we remove key bouncing problem using 04
hardware method?
1
(c) Draw the diagram to interface 4X4 matrix keyboard with 8085 using 8255A 07
and write an assembly language program to find out which key is pressed.
Q.5 (a) Write an Assembly Language Program to generate square wave using 8255. 03
(b) Write an assembly language program to convert BCD number into its 04
equivalent hexadecimal number and store it at memory location 3000H.
(c) Draw and explain he functional block of IC 8255A and also discuss the 07
operating modes and control word format of 8255A.
OR
Q.5 (a) Define Interrupt Service Routine, also mention vector addresses of TRAP, 03
RST7.5, RST6.5, RST5.5 interrupts
(b) Assume that a seven segment display is connected to 8085 through port A of 04
8255A, write an assembly language program to display numbers from 1 to 9
on seven segment display at some particular delay.
(c) Explain with block diagram the 8253 timer chip and its operation 07
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