AU Solved Paper - 8

AU Solved Paper

December-2014

Microprocessors & Microcontrollers

Semester - VI (EEE)

Time: Three Hours]

[Maximum Marks: 100

Answer ALL Questions

PART - A (10 × 2 = 20 Marks)

Q.1 State the function of keyboard interrupts.

Ans. :

Keyboard interrupt is a special case of signal usually generated by the keyboard in the text user interface. This signal is used to generate a hardware interrupt when a key is pressed or released.

Q.2 List the 8085 flags. (Refer section 1.2.1)

Q.3 List any two data manipulation instructions. (Refer section 2.2.2)

Q.4 What is meant by lookup table?

Ans. : A lookup table is an array that replaces runtime computation with a simpler array indexing operation. The savings in terms of processing time can be significant, since retrieving a value from memory is often faster than undergoing an expensive computation or input/output operation.

Q.5 What are the function of USART? (Refer section 11.2)

Q.6 List out the operating modes in 8253 timer/counter. (Refer Two Marks Q.1 of Chapter - 10)

Q.7 Mention the registers used for serial communication in 8051 micro controller. (Refer section 16.6)

Q.8 What are the addressing modes followed in 8051 micro controller? (Refer section 15.1)

Q.9 What are the I/O instructions used in 8051 ? (Refer Two Marks Q.6 of Chapter - 15)

Q.10 State the principle of microcontroller based stepper motor control system. (Refer section 17.4)

PART B (5 x 16 = 80 Marks)

Q.11 a) Explain the architecture of 8086 microprocessor. (Topic not included in new syllabus (Course 2013)) [16]

OR

b) i) Explain the function of 8085 signals. (Refer section 1.3) [8]

ii) Draw and explain the timing diagram of memory write operation. (Refer section 5.4.3) [8]

Q.12 a) Write an assembly language program for

i) Adding a set of n numbers (Refer Lab Experiment 3.1.1)

ii) To generate Fibonacci series using subroutines.  [8+8]

Ans :

MVI D, COUNT ; Initialize counter

MVI B, 00 ; Initialize variable to store previous number

MVI C, 01 ; Initialize variable to store current number

CALL FIBO ; Call subroutine

HLT ; Stop

FIBO : MOV A, B ; [Add two

ADD C ; numbers ]

MOV B, C ; Current number is now previous number

MOV C, A ; Save result as a new current number

DCR D ; Decrement count

JNZ FIBO ; If count # 0 go to FIBO

HLT ; STOP

OR

b) Explain the types of addressing modes in 8085 processor, with suitable examples. (Refer section 2.3)

Q.13 a) Explain about 8279 keyboard display controller in detail, (Refer section 12.3)

OR

b) Explain A/D converter interfacing in detail. (Refer section 13.6) [16]

Q.14 a) Explain the functional block diagram of 8051 micro controller. (Refer section 14.3) [16]

OR

b) Explain interrupt structure of 8051 in detail. (Refer section 16.7) [16]

Q.15 a) Explain the closed loop control of servomotor in detail. (Not in new syllabus) [16]

OR

b) Explain about washing machine control using microcontroller programming. (Not in new syllabus) [16]