Practice questions for Microcontroller Unit Wise

Unit 4

What is the difference 8051 and 8085 ? Explain the low level, high level language with example? Draw the block diagram to create a program, also write use of .list file? What is the advantage of register indirect addressing mode ? Draw and explain IE(Interrupt Enable ) register ? Write short note on simplex, half duplex and full duplex with example?

15 marks question

Draw, neat and clean pin diagram of 8051 and explain all pin function in detail? What is the procedure to write a program for timer 0 or timer 1 in 8051 explain for mode

1 and mode 2?

Explain all addressing mode of 8051 with example also write down advantage of indirect addressing mode of 8051?

Explain all input output port with dual purpose in 8051 draw and explain working to read and write the data in port 1 ?

Assuming that XTAL=22MHz, write a program to generate a square wave of frequency 1 KHz on pin P1.2?

(10)

What do you understand by interrupt and polling? (5)

Write a program in which the 8051 reads data from p1 and writes it to p2 continuously while giving a copy of it to the serial COM port to be transferred serially .Assume that

XTAL =11.0592Mhz .set the baud rate 9600. (10)

Draw the interrupt vector table for the 8051? (5)

Unit 5

What do you understand by PSW register write about all BIT? Write all directives and their role in assembly programming of 8051? If bank 1 register is being used, the default value of stack pointer cannot be used, why? ADD 25H and 70H and find the content of the AC, CY AND P flags? Write all conditional and unconditional jump instruction and what is the difference

between AJMP and LJMP?

15 mark question

(a)Explain the following with suitable example (1) MUL AB (2)DA A (3) DIV AB (4) MOVC A, @A+DPTR (5)DJNZ ?

(10)

(b) What is the difference between AJMP, SJMP, LJMP ? (5)

Write a program to get the x value form P1 and send X^2 (square) to P2 continuously by using look up table? (10)

write a program to add ten 8 bit numbers are stored in the internal RAM form 31H to 3AH .after addition ,MSD will be stored in R2 and LSD will be R3 ? (5)

write a program to find the biggest number in the set of TEN hex number are stored in RAM location 50H onward .The biggest number should finally be saved in 60H. ?

Write down the following Instruction set with proper OPCODE and OPRAND, FUNCTION in 8051 Microcontroller

All program branching instruction (b)All logical instruction All Boolean instruction set Generate a square wave using timer/counter programming with an ON time of 3 ms and

OFF time of 10ms on all port 0.assume an XTAL of 22 MHz ?

(a)Take data in through ports 0, 1, and 2 one after the other and transfer this data serially, continuously? (10)

(b) Explain the SCON serial port control register with proper format? (5)

Unit 6

Write down the pin configuration of LCD? Write a subroutine to write command on LCD? Write a subroutine to write data on LCD? Give the state of RS, E and R/W when sending data character Z to the LCD? Indicate the steps to identify the key pressed? What is the need to convert analog signal to digital signal?

15 marks

Write comparison between PIC, AVR and 8051 MICROCONTROLLER? Write a program to send information HELLO to LCD with MOVC instruction? Explain the pin description for LCD and send HELLO to LCD using the busy flag? Interface the keyboard and program to send ASCII code

(0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F)By using the look up table ?

What do you understand of interrupt write the names of interrupt also write down all steps of executing interrupt?

Give circuit diagram and assembly program to Interface 2x2 keyboard with 8051 microcontroller?

(a)For a given ADC, Vref =2.56 v. calculate the D0-D7 output if the analog input is (5) 1.7 volt (b)2.1 volt