END TERM EXAMINATION

Paper Code: BCA-203

Subject: Computer Architecture

Time: 3 Hours

Maximum Marks: 75

Note:Attempt five questions in all including Q. No. 1 which is compulsory. Select one question from each unit.

Q1. Attempt the following (any ten): (10x2.5=25)
(a) Give difference between RISC and CISC.
(b) List various Logic Microoperations.
(c) Explain Instruction formats, describe its various parts.
(d) An 8 bit register contain the binary value 10011100. What is the register value after an arithmetic shift right? Determine the register value after logic shift left.
(e) Explain the importance of memory hierarchy in computer system.
(f) Draw diagram showing arithmetic pipeline for floating point addition and subtraction.
(g) Explain Register Transfer Language.
(h) Draw 4-bit combinational circuit decrementer.
(i) For a given below 16 bit instruction, give the equivalent four digit hexadecimal code and explain what is the that instruction.
(j) Explain locality of reference in context with cache memory.
(k) A bus organized CPU has 16 register with 32 bits in each, an ALU and a destination decoder.
(i) How many multiplexer are there in A bus and what is the size of each multiplexer?
(ii) How many selection inputs are needed for MUX A and MUX B?
(l) Convert the following arithmetic expression from infix to reverse polish notation.
A + B * (C / D + E * F).

Q2. (a) Design an arithmetic circuit with one selection variable S and two n-bit data inputs A and B. The circuit generates the following four arithmetic operations in conjunction with the input carry Cin. Draw the logic diagram for the first two stages. (6.5)
S
Cin=0
0
1
D=A+B (add)
A+1 (increment)
A-1 (decrement)
A+B+1 (subtract)
(b) Design and describe Control unit of basic computer. (6)

Q3. (a) Draw adder and subtractor and explain its logic circuit. (6.5)
(b) By using flowchart explain its various phases of an instruction cycle and interrupt cycle? (6)

Q4. (a) Explain various Addressing Modes used in Instruction format. Give numerical example to explain. (6.5)
(b) Write a program to evaluate the arithmetic statement with zero, one, two and three address instruction. (6)
X = A-B+C
G+H+K

Q5. (a) What is Pipelining? Explain Instruction Pipelining, and three major difficulties that cause instruction pipeline to deviate from its normal operation. (6.5)
(b) A non-pipeline system takes 50 ns to process a task. The same task can be processed in six-segment pipeline with clock cycle of 10 ns. Determine the speedup ratio of the pipeline for 100 tasks. What is the maximum speed up that can be achieved? (6)

Q6. (a) Explain functioning of Booths Algorithm and Multiply using general multiplication algorithm of Booth. (6.5)
(b) Explain the DMA control with the help of block diagram. (6)

Q7. (a) Explain the difference between the daisy chaining priority and parallel priority interrupts. Draw the diagram to explain their working. (6.5)
(b) Divide using division algorithm 10100011 by 1011. (6)

Q8. (a) Using Block diagram Explain the logic used in the associative memory. (6.5)
(b) How many 128x8 RAM Chip are needed to provide a memory capacity of 2048 bytes including one ROM Chip of 512x8. Diagrammatically explain the memory connection to the CPU. (6)

Q9. (a) What is mapping? Explain three types of mapping procedure used in transformation of data from main memory to cache memory. (6.5)
(b) A computer use RAM chip of 1024x1 capacity. (6)
(i) How many chips are needed to provide a memory capacity of 1024 bytes? Explain how their address lines be connected to provide a memory capacity of 1024 bytes?
(ii) How many chips are needed to provide a memory capacity of 16K bytes? Explain how the chips are to be connected to the address bus?