Hall Ticket No Question Paper Code: AEC021
INSTITUTE OF AERONAUTICAL ENGINEERING
(Autonomous)
Four Year B.Tech V Semester End Examinations (Regular) November, 2018
Regulation: IARE R16
MICROPROCESSORS AND INTERFACING
Time: 3 Hours Max Marks: 70
Answer ONE Question from each Unit
All Questions Carry Equal Marks
All parts of the question must be answered in one place only
UNIT I
1. Explain the register organization model in 8086 with examples.
Explain the function of the following flags in 8086 micoprocessor.
i. Overflow Flag
ii. Direction Flag
iii. Interrupt-enable Flag
iv. Auxiliary carry Flag
2. List out the instruction set types of 8086 microprocessor and explain with example.
Explain the operation of following instruction.
i. MOV AX, DX
ii. ADD
iii. JNZ label1
UNIT II
3. Write an assembly language program to find the largest number from an array of 5 numbers.

Explain the following pins with respect to 8086 microprocessor.
i. ALE
ii. HOLD
iii. IO/
iv. DEN
4. With the help of neat sketch, explain the timing diagram of the write cycle for minimum mode
configuration for 8086 microprocessor
What is function of a typical DMA Controller. Explain mode set register configuration in 8257

Page 1 of 2
UNIT III
5. Explain Mode 1 configuration in 8255 with the relevant timing waveforms.
Describe different external interrupts in 8086 and hence explain what happens when an Interrupt
occurs.
6. Draw the block diagram of 8259 and explain the following
i. IRR
ii. ISR
iii. IMR
iv. Priority Resolver
Interface an ADC 0808 with 8086 using 8255 ports. Use port A of 8255 for transferring digital
data output of ADC to the CPU and port C for control signals.Assume that an analog input
is present of the ADC and a clock input of suitable frequency is available for ADC.Draw the
interfacing diagram and write the necessary ALP to read the analog voltage and store in AL
register.
UNIT IV
7. Compare Synchronous and Asynchronous Transmission with examples.
Explain the bit configuration mode register of 8251 with the help of neat diagram
8. Explain the bit configuration of command instruction of 8251.
Write a assembly language program to initialize 8251A at address 00FFH for the following specifications.

i. Character length- 6 bits
ii. Parity even
iii. Baud rate 64 x
iv. Stop bit I
v. DTR and RTS asserted
vi. Error flag reset
vii. Trasmitterenable
UNIT V
9. Differentiate the real mode and protected operation of advanced microprocessor.
With neat sketch explain the address conversion mechanism takes place in advanced microprocessor.

10. Compare the features of 80286 and 80386 microprocessor.
Draw the architecture of 80386 processor and explain each block with its features.