GTU previous year question papers -BE- Sem-Vth -Microcontroller & Interfacing -June- 2011

GTU previous year question papers


B. E. Sem. – V – Examination – June- 2011

Subject code: 151001

Subject Name: Microcontroller & Interfacing


1. Attempt all questions.

2. Make suitable assumptions wherever necessary.

3. Figures to the right indicate full marks.

Q.1 (a) What are the interrupts available in the 8051 microcontroller?

Explain interrupt enable (IE) SFR and Interrupt priority (IP) SFR.                                    

(b) Explain operation of timer in mode 1. Discuss programming steps to

generate time delay using mode 1. Write program to generate delay

of 0.1 second using timer 0 in mode 1.                                    

Q.2 (a) Explain basic architecture of 8051 microcontroller. Discuss RAM structure.                                     

(b) Explain pin configuration with circuit diagram for port 0 and port 1                                      


(b) Draw and explain RESET and clock circuit of 8051 microcontroller.

What is the purpose of capacitor in RESET circuit?                                    

Q.3 (a) Answer the following questions

[1] What is the purpose of EA pin in 8051 microcontroller?

[2] What is the purpose of EA bit in IE SFR?

[3] What is the function of ALE signal?

[4] Why pull-up resistors are necessary with port P0 in

8051 microcontroller

[5] What is the function of SMOD bit in TCON SFR?

[6] What is the function of GATE bit in TMOD SFR?

[7] Write instruction to select register bank 2.                                    

(b) Explain following instructions

[1] SWAP A [2] ADD A,B [3] DIV AB [4] MUL AB

[5] RL A [6] XCHD A,R0 [7] MOV A,@R0                                    


Q.3 (a) Write program to generate square wave on port pin P2.0 with

frequency of 10 KHz and duty cycle 50%. Use timer interrupt. Use

timer 0 in mode 2. Assume crystal frequency 12 MHz.                                    

(b) Draw interfacing diagram to interface push-button switch at port pin

P3.3 and relay with transistor circuit at port pin P2.0. Write program

such that when push-button key is pressed, relay should become

ON. When push-button key is pressed again relay should become

OFF (i.e. toggling of relay by push-button switch).                                    

Q.4 (a) Explain interfacing of analog to digital converter (ADC) with

microcontroller. Write program to read analog value from ADC on

port P1 and display digital values on LEDs connected at port P0                                     

(b) Draw and explain interfacing of 4×4 matrix keyboard with 8051

microcontroller. Write program to read switch.


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