EL/VI/CC/18 Student’s Copy
2024
( CBCS )
( 6th Semester )
ELECTRONICS
TENTH PAPER
( Computer Organization and Microprocessor )
Full Marks : 75
Time : 3 hours
The figures in the margin indicate full marks for the questions
Use of Simple Calculator Allowed
( SECTION : A—OBJECTIVE )
( Marks : 10 )
Tick (3) the correct answer in the brackets provided : 1×10=10
1. The _____ supervises the transfer of information among the registers and
instructs the ALU as to which operation to perform.
(a) CPU ( )
(b) microprocessor ( )
(c) control unit ( )
(d) microcontroller ( )
/530 1 [ Contd.
2. Binary equivalent to decimal 23 is
(a) 10111 ( )
(b) 11011 ( )
(c) 11101 ( )
(d) 11110 ( )
3. Flash memory is
(a) read/write memory ( )
(b) read-only memory ( )
(c) secondary memory ( )
(d) backup memory ( )
4. If the memory chip size is 1024 × 1, the number of memory chips needed to
design 8 K-byte memory is
(a) 16 chips ( )
(b) 24 chips ( )
(c) 32 chips ( )
(d) 64 chips ( )
5. The instruction LXI SP, 16 bit means
(a) load stack pointer with 16 bit ( )
(b) load memory with 16 bit ( )
(c) load 16 bit to stack pointer ( )
(d) load 16 bit to memory ( )
6. The addressing mode used in MVI R is
(a) register addressing ( )
(b) direct addressing ( )
(c) immediate addressing ( )
(d) indirect addressing ( )
/530 2 [ Contd.
7. The highest priority interrupt in 8085 is
(a) TRAP ( )
(b) RST 6·5 ( )
(c) INTR ( )
(d) RST 7·5 ( )
8. 8-bit opcode instruction being executed is contained in
(a) stack pointer ( )
(b) instruction register ( )
(c) program counter ( )
(d) general purpose register ( )
9. ______ converts the programs written in assembly language into machine
instructions.
(a) Converter ( )
(b) Assembler ( )
(c) Machine compiler ( )
(d) Interpreter ( )
10. In the 8085 microprocessors, which of the following buses are multiplexed
(time shared)?
(a) Control bus and higher address bus ( )
(b) Data bus and control bus ( )
(c) Higher bus and data bus ( )
(d) Lower address bus and data bus ( )
/530 3 [ Contd.
( SECTION : B—SHORT ANSWERS )
( Marks : 15 )
Answer the following : 3×5=15
UNIT—I
1. Fill in the blanks :
(a) The ASCII code is a 7-bit code for ______. (numbers/alphanumeric/
binary)
(b) A ______ is a group of devices that stores digital data. (memory/
register)
(c) ______ is abbreviation for binary digit. A byte is a string of ____ bits.
(bit/byte/4/8)
OR
2. Define instruction set. How many types of data transfer operations are
there? Explain with examples.
UNIT—II
3. Elaborate the classification of memory organization of a computer in brief.
OR
4. Briefly explain the stack memory organization with example.
UNIT—III
5. What are some typical distinguishing characteristics of RISC organization?
OR
6. Explain the working of ring counter with suitable diagram.
UNIT—IV
7. Write an assembly language code to move the data of an accumulator to
register C and then load the data of register B to accumulator. Finally add
the contents of register C to the content of register A and increment the
result.
/530 4 [ Contd.
OR
8. What is the function of accumulator? While executing a program, when the
8085 MPU completes the fetching of the machine code located at the
memory address 2057H, what is the content of the program counter?
UNIT—V
9. Differentiate high-level and low-level languages.
OR
10. What are compiler, linker and interpreter?
( SECTION : C—DESCRIPTIVE )
( Marks : 50 )
Answer the following : 10×5=50
UNIT—I
1. (a) Explain the machine cycle of the following 3-byte instruction when it is
executed : 6
Opcode Operand Bytes Machine T-states Operation
Cycle
STA 2065H 3 4 13 Stores (writes) the contents of accumu-
lator in memory location 2065H
(b) Elaborate operand data type used in modern computers. 4
OR
2. (a) Briefly explain the digital computer with proper block diagram. 6
(b) What is word (word length) in a computer? How many combinations of
words will a computer have if its word length of 8-bit? 4
UNIT—II
3. (a) Distinguish between volatile memory and non-volatile memory. 5
(b) What is a control word in control unit? Illustrate it with suitable
example. 5
/530 5 [ Contd.
OR
4. Explain the following in brief : 2×5=10
(a) Memory Buffer Register (MBR)
(b) Instructor Register (IR)
(c) Program Counter
(d) Accumulator
(e) Cache memory
UNIT—III
5. How many types of memory addressing schemes are there in a processor?
Elaborate. 10
OR
6. (a) What is a stack pointer? Explain it with suitable example. 5
(b) Explain the concept of paging. 5
UNIT—IV
7. (a) With neat diagram, briefly explain the pinout of Intel 8085
microprocessor. 7
(b) What are the different clues to recognize the number of bytes in an
instruction of Intel 8085 microprocessor? 3
OR
8. (a) Explain the execution of any of the I/O instruction with proper machine
cycle and timing diagram. 8
(b) Differentiate between ASCII code and BCD code. 2
UNIT—V
9. Write a short note on Instruction set of 8085 microprocessor. 10
OR
10. (a) Differentiate among compiler, linker and interpreter. 6
(b) Write an assembly language instruction to load two hexadecimal
numbers 48H and 32H in register B and register A respectively.
Subtract the numbers and display the result at the LED output port
PORT2 (02H). 4
HHH
/530 6 24G—30
