This document contains assignment questions for several units of a course on the 8051 microcontroller. It includes questions about RISC and CISC architectures, Harvard and Princeton architectures, features of the 8051 including its oscillator circuit and timing diagram, addressing modes, instructions, register bank, bitwise logical operations, timers/counters, serial communication, interrupts, interfacing with displays, DAC, ADC, and the 8255 peripheral interface adapter. The questions cover topics ranging from basic microcontroller concepts to programming and interfacing the 8051 chip.

1. Microcontroller 10ES42
Department of EEE, SJBIT Page 1
Assignment Questions
Unit -1
1. What are the advantages of RISC and CISC processor architecture?
2. Distinguish between Harvard and Princeton architecture with diagram.
3. With a block diagram list the specific features of 8051 Explain the oscillator
circuit and timing diagram of 8051 microcontroller
4. Draw clock circuit of 8051
5. Explain with pin diagram different pins of 8051
UNIT -2
1. Explain different addressing modes
2. What is indexed addressing mode
3. Explain how is PSW affected when following instructions are executes- addc,
sub, rrc, djnz
4. Write a program to add first 10 prime numbers
5. Explain the functions of the following pins of 8051 1) EA 2) ALE 3) RST ( 7
marks)
6. Draw a schematic to interface external ROM and RAM to 8051. How to access
them?
7. Mention the function of the following instructions of 8051 CPU: 1) MOVC
A,@A+DPTR 2)CJNE 3)MUL AB 4) DJNZ 5) A CALL
8. List out the address range of bit addressable memory locations
9. Explain register bank of 8051
UNIT 3
1. How bit level logical operations can be done in 8051
2. write a subroutine to decrement the contents odf DPTR
3. Write the different conditional JUMP instructions in 8051
4. Write a program to logically OR the contents of ports P1 and P2 and put the
result in external RAM location 0100H

2. Microcontroller 10ES42
Department of EEE, SJBIT Page 2
5. Find the sum of values 03h, 56h, 95h put the sum in R0 and R5
6. Write an ALP to find square root of a numbers and store in R0
UNIT 4
1. What are the advantages of C programming
2. What are the disadvantages of C programming
3. Write c program to calculate square and cube of a number
4. Write 8051 assembly language program and C program to send a 8 bit numbers
to P1
5. Explain the data types in C
6. What are the different preprocessor directives in C.
UNIT 5
1. Distinguish counting and timing requirements , explain the modes of operation of
timer/counter of 8051 with diagram.
2. What are the different modes of timer
3. Differentiate between timer and counter
4. For a machine cycles of 1.085microsec find the timer delay in following
subroutine
5. Explain the timer structures of 8051 with TMOD register ( 10 marks) jan 09
UNIT 6
1. explain the different steps to receive data serially using 8051
2. Explain serial communication
3. What are the advantages and disadvantages of serial communication
4. What are the serial ports in 8051
5. What is serial communication? How is this achieved with 8051 using RS232
standards
6. What is need of max232

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Department of EEE, SJBIT Page 3
7. Explain handshaking signals
8. explain the format of SCON register in details
UNIT 7
1. Explain the two methods by which overrun can be deleted
2. What are different software interrupts
3. What are hardware interrupts
4. Explain maskable and unmaskable interrupts
5. interface a 2 digit 7 segment display and a switch to 8051. Write an ALP to show
up counting when switch ON otherwise down counting
6. What is ISR
7. What is the default priority assigned to various interrupt after reset? Is it
possible to alter priority
UNIT 8
1. Interface 7 segment display to 8051 and write program to display counter
2. Implement BCD counter using 7 segment display
3. Generate Square wave using DAC
4. Write C program to measure temperature using ADC and 8051
5. What is 8255, explain its interfacing with 8051