JNTU Question Previous Papers B Tech EC 3rd Year 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 add two 16-digit packed BCD numbers

(b) Write an ALP in 8086 to divide a 32-bit number by a 16-bit number [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) Write the BSR control word to set bit 3 of port C and also write the BSR control word to reset bit 3 of port C. Introduce a 1m sec delay between set and reset of bit 3 of port C.

(b) Briefly explain the application examples of mode 0, mode 1 and mode 2 of

8255. [8+8]


6. (a) Explain the importance of 8259 interrupt controller and explain how does it

handle the interrupt.

(b) Give an interfacing diagram, which shows the connections between 8086 and

8259. [10+6]


7. (a) Discuss the types of serial communication?

(b) Write an 8086 instruction sequence for receiving 50 characters using 8251 and

store them in memory at location 2080H.. [8+8]


8. (a) Discuss in detail about serial port operation in 8051 microcontroller.

(b) Explain in detail about the interrupt structure of 8051. [8+8]

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