EC1362 MICROPROCESSOR AND MICROCONTROLLER question papers Anna university question papers Download

B.E/B.Tech DEGREE EXAMINATION NOVEMBER/DECEMBER 2007

Sixth Semester
                                  
Electrical and Electronice Engineering

EC 1362 -- MICROPROCESSOR AND MICRO CONTROLLER

(Regulation 2004)
Time: Three hours                                                    Maximum marks: 100
Answer ALL questions

PART A (10 x 2 =20 marks)

1. If a 5 MHz crystal is connected with 8085 ; what is the value of system clock ftequency and one T-state?

2. What is the functuon of SIM instruction in 8085?

3. Write the operation carried out when 8085 executes RSTO instrection.

4. What is stack? And what is the function of stack pointer?

5. Write the BSR control words to set PC0 and to reset PC4 in 8255.

6. Write the format in which data is transmitted in asunchronous mode by 8251.

7. What is the function of ITX bit in the TCON register of 8051?

8. What is the function of SM 2 bit in the SCON register of 8051?

9. What is the operation carried out when 8051 executes the instruction MOVC A, @ A + DPTR?

10. How keyboard debouncing is done by software?

PART B (5 x 16 = 80)

11 (a) Explain the architecture of 8085 microprocessor in detail with neat block diagram. (16)
(or)
(b) (i) Interface a 8KX8 EPROM IC and 2KX8 RAM IC with 8085 such that the starting address assigned to them are 0000H and 4000H respectively using address decoder having NAND gate and inverters. (8)

(ii) Draw the timing diagram of I/O read cycle in 8085 and explain it. (8)

12.  (a) Explain the operations carried out when 8085 executes instructions (16)

(i) MOV A, M

(ii) XCHG

(iii) DAD B

(iv) DAA

(v) POP PSW.
(or)
(b) Write 8085 assembly language program to find the seven segment codes for the lower and upper nibble of the given 8-bit binary number using look up table technique and store the result in memory. (16)

13 (a) Explain the architecture of USART (8251) in detail with neat block diagram and describe the mode, command and status control words in it. (16)
(or)
(b) Interface an 8-bit DAC with 8085 microprocessor using 8255 and write assembly language programs to generate square wave of 1 KHZ and triangular wave of 100 Hz. The crystal frequency connected to 8085 is 6 MHZ (16)

14. (a) Explain the interrupt structure in 8051 in detail. (16)
(or)
(b) (i) Explain the different addressing modes in 8051 in detail. (8)

(ii) Describe the different modes of operation of timers in 8051. (8)

15. (a) Explain the operation carried out when the following instructions are executed by 8051. (16)

(i) MOVX @ RO,A

(ii) MOVC A, @ A + PC

(iii) RLC A

(iv) CJNE A, 50 H, L2

(v) JBC 20 H, L3

(vi) XCH A, 30H where L2 and L3 are labels.
(or)
(b) Interface a 20 2 LCD with 8051 micro controller and write assembly language program to display the following message in it at the middle. (16)

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