Microprocessors and Peripherals - Dec 2014

Electronics Engineering (Semester 4)

TOTAL MARKS: 80
TOTAL TIME: 3 HOURS (1) Question 1 is compulsory.
(2) Attempt any three from the remaining questions.
(3) Assume data if required.
(4) Figures to the right indicate full marks. 1 (a) Explain flag register used in 8085 processor.(5 marks) 1 (b) Define the Instruction cycle, Machine cycle & T State?(5 marks) 1 (c) What is REP prefix? How it functions for string instructions?(5 marks) 1 (d) Explain the difference between a JMP instruction and CALL instruction.(5 marks) 2 Design a 8086 based system with following specification.
� CPU at 10 MHz in minimum mode operation
� 32 KB SRAM using 8 KB devices
� 64 KB EPROM using 16 KB devices
� One 8255 PPI for keyboard interface
Design system with absolute decoding. Clearly show memory address map and I/O address map. Draw a neat schematic for chip selection logic.(20 marks) 3 (a) Explain the Interrupt structure of 8086 processor?(10 marks) 3 (b) Discuss the various addressing modes of 8086. What are displacement, based and index? What is an effective address or offset?(10 marks) 4 (a) Write program to find out largest number in an array.(10 marks) 4 (b) Write program to find out number of times letter 'e' exist in the string 'exercise', Store the count at memory.(10 marks) 5 (a) Explain the interface of 8087 co-processor with 8086 processor?(10 marks) 5 (b) Sketch and explain the interface of PPI 8255 to the 8086 microprocessor in minimum mode. Interface four 7 segment LEDs to display as a BCD counter(10 marks) 6 (a) Explain the function of various flags of 8086 microprocessor.(5 marks) 6 (b) The function of the pins S2, S1 & S0 of 8086.(5 marks) 6 (c) Operation modes of 8237 DMA Controller.(5 marks) 6 (d) Draw and explain the instruction template format of 8086.(5 marks)