JNTU B-Tech II Semester Examinations,Microprocessors And Interfacing, Apr/May 2008


JNTU B.Tech II Semester Examinations,

Microprocessors And Interfacing

, Apr/May 2008

 ( Common to Electronics & Communication Engineering )

Time: 3 hours Max Marks: 80

Answer any FIVE Questions

All Questions carry equal marks


1. (a) Explain the functioning of following resisters of 8086 Microprocessor

i. Segment resisters

ii. Pointer resisters

iii. Index resisters

(b) Discuss briefly about pre-fetch queue in 8086 [12+4]


2. (a) Describe the following addressing modes with some examples.

i. Indexed addressing with displacement

ii. I/O port addressing

(b) Explain the meaning of the following 8086 instructions

i. mov [3845h], bx

ii. add ax, [si]

iii. mov bx, 2956h

iv. adc ax, bx [8+8]


3. (a) Write an ALP in 8086 to find a maximum number in the array of 10 numbers

(b) Write a recursive program in 8086 ALP to find the sum of the first “n integers [8+8]


4. (a) With relevant pin diagrams explain the minimum and maximum mode operations of 8086

(b) Explain briefly about DMA data transfer method. [12+4]


5. (a) Distinguish between Mode set control word and BSR control Word of 8255?

(b) Write an ALP in 8086 to generate a symmetrical square wave form with 1KHz frequency? Give the necessary circuit setup with a DAC? [8+8]


6. (a) Discuss in detail about the interrupt structure of 8086?

(b) Describe the interrupt vector table of Intel Processors? [8+8]


7. (a) What are the important features of 8251?

(b) Explain the following control words of 8251. With suitable Examples.

i. Mode word

ii. Command word [6+10]


8. (a) Explain the internal and external program memory as well as data memory of

8051 with the diagram showing their capacities.

(b) Draw the diagram to Interface Program memory of 16K x 8 EPROM to 8051and give its memory map. The address of memory map should start from 0000H. [8+8]

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