R09 - December, 2011 - Regular Examinations - Set - 1.

B. Tech III Year I Semester Examinations, December-2011
MICROPROCESSORS AND INTERFACING
(COMPUTER SCIENCE AND ENGINEERING)
Time: 3 hours Max. Marks: 75
Answer any five questions
All questions carry equal marks
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1.a) Explain the segmented memory organization structure of 8086 and also discuss the advantages
b) What are macros? Write an 8086 macro to produce 25ms of delay without changing any of the processor registers used in main program. Consider the 8086 is operating on a 4MHZ clock. [7 8]
2.a) Distinguish between the following.
i) Jump and Loop Instructions
ii) Shift and Rotate Instructions.
b) Write an Assembly Language Program to find the transpose of a 3X3 matrix.
[7 8]
3.a) Explain about the read and write cycle timing diagrams of maximum mode. What is the need of bus controller in the maximum mode?
b) Explain the following modes of DMA Transfer.
i) Block transfer mode ii) memory to memory transfer. [7 8]
4.a) Interface a typical 12 bit DAC with 8255 and write a program to generate a triangular waveform of period 10ms. The CPU runs at 5MHz clock frequency.
b) Interface a 26-keys keyboard with 8279. The keys represent the alphabets ā€˜aā€™ to ā€˜zā€™. Write an 8086 ALP to find out the ASCII equivalent of the alphabet corresponding to the pressed key. The 8086 system runs at 6 MHz while the 8279 should work at 200 kHz. Will the internal prescalar reduce 6 MHz to 2kHz? If any external prescalar is required, design it with minimum hardware. [7 8]
5.a) Explain the synchronous mode transmit and receive data format of 8251.
b) Explain the architecture of USART 8251 with neat diagrams. [7 8]
6.a) Explain the following important operational features of 8051 in detail.
i) PSW ii) TMOD iii) TCON iv) SCON
b) Explain how 8051 differentiates between external and internal program memory. [7 8]
7.a) Explain the role of Timer1 and SCON register in serial data transfer.
b) Write an assembly language program using program timer1 of 8051 to generate square waveform of 10KHz. Assume XTAL=20MHz. [7 8]
8. Write short notes on the following:
a) Interrupt structure of 8051.
b) Assembler Directives
c) String Manipulation Instructions. [15]
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    Sep 29, 2012
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    Sep 29, 2012
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