R09 - December, 2011 - Regular Examinations - Set - 3.

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 all the flags and list the internal registers in 8086
b) Explain the instructions related to arithmetic and logical shift. [8 7]
2.a) Explain REP, REPZ and REPNZ prefixes used along with string instructions and also give examples
b) Explain the following directives
i) ENDS ii) ENDP iii) PTR directive iv) DD [8 7]
3.a) Sketch and explain the 8086 bus activities during the read and write machine cycles in minimum mode.
b) Explain DMA function in 8086 microprocessor with timing diagrams. [7 8]
4.a) Sketch the Interfacing diagram of an 8 bit ADC to 8086. Get the digital data at port A of 8255. Derive control signals from port C and write an 8086 assembly program.
b) Explain the BSR Control word of 8255. [7 8]
5.a) Sketch and explain the interface of PIC 8259 to the 8086 microprocessor in minimum mode. Show the cascading of additional two 8259s to provide more Interrupts and also write an assembly language program.
b) Explain about DOS and BIOS interrupts with suitable examples. [7 8]
6.a) What is a USART? With a block diagram explain the architecture of USART.
b) Draw the circuit of TTL to RS232 and explain the necessity of this interface. [7 8]
7.a) Explain How Harvard architecture is implemented in 8051 and list the features of 8051
b) Write an 8051 assembly program to evaluate the factorial of an integer number N using recursive procedure. [7 8]
8. Write short notes on the following
a) Interrupt structure of 8051
b) IEEE 488 GPIB
c) Procedures and macros. [15]
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