B.E./B.Tech. DEGREE EXAMINATION, NOVEMBER/DECEMBER 2010
Computer Science and Engineering
CS2252 – MICROPROCESSORS AND MICRO-CONTROLLERS
(Common to Information Technology)
Time : Three hours Maximum : 100 Marks
Answer ALL questions
PART A – (10X2=20 Marks)
1. Give any two single byte instructions that clear the accumulator register of 8085.
2. List the machine cycles involved in the execution of the following 8085 instructions: PUSH PSW; MOV A,M.
3. List the pointer and index registers of 8086 architecture.
4. Identify the addressing modes involved in the following 8086 instructions: MOV AX,0005H; MOV AX,50H [BX][SI].
5. What are the two internal sections of 8087 architecture?
6. What is the role of CCP in 8089 architecture?
7. What are the signals and instructions available in 8085 processor for serial I/O communication?
8. What signals are required between a 8085 processor and an interrupt controller for interrupt driven data transfer?
9. What are the functions of the following signals of 8051? ALE/PROG, PSEN.
10. What are the sources of interrupts in 8051?
PART B – (5X16=80 Marks)
11. (a) (i) List and explain the functions of flags in 8085 processor. (8 Marks)
(ii) Write an assembly language program using 8085 instruction set to convert a string of ASCII characters into its hexadecimal equivalent. (8 Marks)
(b) (i) Identify the addressing modes and the number of T- states required for the following instructions of 8085: MOV M,A; LXI SP, addr:LDAX D; ORA B. (8 Marks)
(ii) Discuss the features of 8085 processor for the support of interrupts and DMA. (8 Marks)
12. (i) Explain the register organization of 8086 processor in detail. (8 Marks)
(ii) Describe the various addressing modes of 8086 processor with suitable examples for each. (8 Marks)
(b) (i) What is the use of interrupts in microprocessor systems? With suitable examples explain the sequence of operations done by a microprocessor when it is interrupted. (8 Marks)
(ii) Explain how BIOS function calls are invoked in assembly language programs. (8 Marks)
13. (a) (i) Explain the exception handling feature of 8087. (8 Marks)
(ii) Write a detailed note on the data types supported by 8087 in detail. (8 Marks)
(b) (i) With a neat sketch explain the general interconnections between 8086 and 8089. (10 Marks)
(ii) Distinguish between loosely coupled and closely coupled multiprocessor systems with suitable examples. (6 Marks)
14. (a) (i) With a neat sketch, show all the interconnections required between a 8085 processor and a RAM of size 4KB mapped in the address range 2000H-2FFFH. (8 Marks)
(ii) Explain the data transfer on a parallel printer interface using a timing diagram. (8 Marks)
(b) (i) What are the signals a microprocessor should have to support DMA? List and explain the sequence of operations carried out during a DMA transfer. (8 Marks)
(ii) Explain the four modes of keyboard operation in 8279. (8 Marks)
15. (a) (i) Bring out the features of special function registers of 8051 microcontroller. (8 Marks)
(ii) With a neat sketch of a schematic diagram, explain the functions of various signals of 8051. (8 Marks)
(b) (i) Describe the various interrupts and their associated priorities in 8051 microcontroller. (8 Marks)
(ii) Write brief notes on ADCs mid DACs along with their interface details. (8 Marks)
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