Visvesvaraya Technological University B.E Fourth semester Common to EC/TC/ML MICROCONTROLLERS Model Question Paper-1

Fourth semester BE Degree Examination,
(IV Sem Common to EC/TC/ML)

Model Paper-I

Duration : 3 Hrs Max Marks: 100

Answer any five questions choosing at least two from each part

QI.(a) Give the comparison between microprocessor and microcontroller.
b) With neat block diagram explain the architectural features of 805 I
(10 M)
c) Write the program status word format of 8051 with individual bit
operations (4M)
Q2. a) Differentiate between the following instructions of 8051
(i) SWAP and XCHG
(ii) MOVX and MOVC
(iii) Bit level ANL and byte level ANL (6M)
b) Write an assembly language program to find the square root of a
number and store in Ro . (5M)
c) What is the principle of stack memory? .Explain with the help of
PUSH & POP instructions. (6M)
d) Calculate time required to PUSH DPTR, B, A, PSW and PC on to the
stack. Assume XTAL= I I .0592 MHz (3M)
Q3. a) What are the different ranges associated with CALL
instructions of 8051?. (6M)
b) Give different steps followed by 8051 in response to interrupt.
How we can enable or disable the interrupts? ( 6M)
c) Write an assembly program to sort an array in an ascending
order. (8M)
Q4. a) What are the different ways to introduce a delay in 8051 C.
Give the three factors which affect the accuracy of the delay.
( 6M)
b) Write an 8051 C program to toggle the bits of P1 ports continuously
with a 250 ms delay. (6M)
c) Write an 8051 C program to get an 8 bit binary number from P1 ,
convert it in to ASCII and save the result in memory location 50H.
Q5. a) What are counting & timing requirements? Explain modes of
operation of timer / counter with relevant block diagrams
b) Assuming XTAL = 11.0592MHz generate a square wave of 2
KHz on P2.3 (6M)
c) Assuming XTAL = 11.0592MHz indicate when the TF0 flag is
raised for the following program.
MOV TL0 # 10H
MOV TH0, # 1CH
Q6. a) What is asynchronous serial communication and data
framing (6M)
b) Write RS232 standards for DB9 pin out. (8M)
c) Write an 8051 C program to receive byte of data serially & put
them on P1. Set the baud rate to 4800, 8 bit data, 1 stop bit.
Q7. a) What are external interrupts ? How they are handled in 8051?
How level triggered interrupts are reset? How to set INT1 as edge
triggered interrupt? (8M)
b) Write a program using interrupts to do the following.
i) Receive data serially and set it to P0.
ii) Have P1 port to read and transmitted serially and copy
given to p2.
iii) Make timer 0 generate a square wave of 5 KHz
frequency on P0.1.
Assume XTAL = 11.0592MHz (12M)
Q8 a) Draw the block schematic of stepper motor interfaced to
8051 at port P0 for the rotation of 45 degrees in
anticlockwise direction. Write a C program for the same.
Assume motor step angle as 1.8 degrees per step.
b) Interface 2x16 line LCD to 8051. Write a C code to display
" WELCOME" on LCD. (10M)


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