MICROPROCESSORS AND MICROCONTROLLERS - April / May 2010

Anna University

B.E./B.Tech. DEGREE EXAMINATION, APRIL/MAY 2010 

Fourth Semester 

Computer Science and Engineering 

CS2252 — MICROPROCESSORS AND MICROCONTROLLERS (Common to Information Technology) 

(Regulation 2008) 

Time: Three hours Maximum: 100 Marks

Answer ALL Questions

PART A — (10 × 2 = 20 Marks)

1. Assume that the accumulator contains data bytes 82H and the instruction MOV C, A (4FH) is fetched. List the steps in decoding and executing the instruction.

2. What are the second bytes in the instruction IN and OUT of  8085 microprocessor? 

3. Draw the 8086 flag register format.

4. List different types of 8086 hardware interrupts.

5. Compare closely coupled configuration with loosely coupled configuration.

6. Mention the need for co-processor in a microprocessor based system.

7. Can an input port and an output port have the same port address? Justify.

8. Why is each channel in DMA controller restricted to 16K bytes of data transfer?

9. With XTAL = 11.0592 MHz, what value should be loaded into TH1 to have 9600 baud rate?

10. How do you select the register bank in 805l microcontroller?


PART B — (5 × 16 = 80 Marks)

11. (a) (i) Write an 8085 assembly language program with flowchart for the following: Six bytes are stored in memory locations starting at XX50H. Add all the data bytes. Use register B to save any carry generated while adding the data bytes. Store the sum at two consecutive memory locations, XX70H and XX7IH. Data (H): A2, FA, DF, E5, 98, 8B. (8)

(ii) Write a program to generate a continuous square wave with the period of 500µ s . Assume the system clock period is 325ns and use bit D0 to output the square wave. (8)

Or (b) (i) Explain the following 8085 instructions with JP, JPO, CM, RPE. DAA, XCHG. SPHL and PCHL. an example (8)

(ii) Draw the timing diagram for the MVI A, 32h and OUT 01h. instruction (8)

12. (a) (i) Draw the internal block explain. diagram of 8086 microprocessor and explain (8)
(ii) Explain any eight assembler directives of 8086 microprocessor. (8)

Or

(b) (i) Give three examples for the following 8086 microprocessor instructions: String Instructions, Process Control Instructions, it with 8087 control word and status word formats. (12)

(ii) Give two examples for packed decimal data transfers and integer data transfers of an 8087 Co-processor. (4)

Or 

(i) Program Execution Transfer Instructions. Instructions and Bit Manipulation (12)
(ii) How does one define and microprocessor? Call Macro parameters of 8086 (4)

13. (a) (i) Draw the internal block diagram of 8087 Co-processor and explain

(or)

(b) Draw the architecture of 8089 I/O Co-processor and explain. (16)

14. (a) Draw the block diagram of 8279 Keyboard/Display controller and explain how to interface the Hex Key Pad and 7-segment LEDs using 8279. (16)

Or

(b) (i) Draw the functional block diagram of 8254 timer and explain the different modes of operation. (8)

(ii) Draw the block diagram of 8259A and explain how to 8259A. program (8)

15. (a) (i) Explain the memory structure of an 8051 Microcontroller. (8)

(ii) How does one interface a 16 × 2 LCD Display using 8051 Microcontroller? (8)

Or

(b) (i) Explain the on-chip timer modes of an 8051 Microcontroller. (8)

(ii) Explain how to interface an 8-bit ADC with 8051 Microcontroller. (8)