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) With a neat architectural diagram explain the functioning of an 8086 microprocessor
(b) Compare the flag resisters of 8086 & 8085 [10+6]
2. (a) Explain the following 8086 instructions with examples.
(b) Differentiate between procedures and macros using certain examples. [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) Explain how static RAMs are interfaced to 8086. Give necessary interface
diagram assuming appropriate signals and memory size
(b) Explain the need of DMA. Discuss in detail about DMA data transfer method [8+8]
5. (a) Draw the internal block diagram of 8255 and explain its working
(b) Explain how a keyboard is interfaced to 8086 through 8255. Draw the necessary interface circuit? [8+8]
6. (a) How many Initialization Command words are required for a single 8259 in an 8086 based system? Explain their format?
(b) Discuss the following interrupts?
i. Single step Execution
ii. Interrupt on Overflow. [10+6]
7. (a) Give the specifications of RS232C?
(b) Explain about line driver and line receiver used in serial communication?
(c) Give the status register of 8251 and explain each bit. [4+6+6]
8. (a) Discuss about various addressing modes of 8051.
(b) Explain the interrput structure of 8051 [8+8]