B.E./B.Tech. DEGREE EXAMINATION, NOVEMBER/DECEMBER 2011.
Electrical and Electronics Engineering
EE 2354 — MICROPROCESSORS AND MICROCONTROLLER
Time : Three hours Maximum : 100 marks
Answer ALL questions.
PART A — (10 × 2 = 20 marks)
1. Draw the schematic of latching low-order address bus in 8085 microprocessor.
2. If the stack segment register contains 3000h and stack pointer register contains 8434h, what is the physical address of the top of the stack in 8086 microprocessor?
3. Why do we need look-up table?
4. How are the 8085 instructions classified according to the functional categories?
5. Draw the 'Mode Word' format of 8251 USART.
6. State the use of ISR and PR registers in 8259 PIC.
7. List the on-chip peripherals of 8051 microcontroller.
8. What are the addressing modes of 8051 microcontroller?
9. Why do we need opto-isolator circuit between microcontroller and the Stepper motor?
10. Mention the I/O instructions of 8051 microcontroller.
PART B — (5 × 16 = 80 marks)
11. (a) (i) Explain in detail the 8085 interrupt structure. (8)
(ii) Draw the timing diagram for IN and OUT instruction of 8085 and explain. (8)
(b) (i) Draw the internal block diagram of 8086 and explain the bus interface unit and execution unit. (8)
(ii) How address decoding is done in memory Interface. (8)
12. (a) (i) Write a program to count from 0 to 9 with one second delay between each count. At the count of 9, the counter should reset itself to 0 and repeat the sequence continuously. Assume the clock frequency is 1 MHz. (8)
(ii) Write a program with a flowchart to multiply two 8-bit numbers.(8)
(b) (i) Compare the similarities and differences of CALL and RET instructions with PUSH and POP instructions. (8)
(ii) Sixteen bytes are stored in memory locations at XX50h to XX5Fh. Transfer the entire block of data to new memory locations starting at XX70h. (8)
13. (a) (i) Explain the operating modes of 8255 programmable peripheral interface. (8)
(ii) Draw the logical block diagram of 8279 keyboard display controller and explain. (8)
(b) (i) Draw the control word of 8253 timer/counter and explain the operating modes of 8253 timer/counter. (8)
(ii) Why do we need A/D converter and D/A converter? Draw the block diagram to interface 8085 microprocessor with A/D convertor and D/A convertor. (8)
14. (a) (i) Explain the program memory and data memory structure of 8051 microcontroller. (8)
(ii) Draw the pin diagram of 8051 microcontroller and explain its port structure. (8)
(b) (i) Draw the TMOD register format and explain the different operating modes of timer in 8051 microcontroller. (8)
(ii) Explain how serial communication is performed in 8051 microcontroller. (8)
15. (a) (i) Explain with a program to rotate the stepper motor in both clockwise and anticlockwise direction using 8051 microcontroller. (8)
(ii) How to interface a 7 segment display using 8051 microcontroller. (8)
(b) (i) How 8051 is used in washing machine control? (8)
(ii) How do you interface a 4 × 4 matrix keyboard using 8051 microcontroller? (8)