EC6009 Advance Computer

EC6009 Advance Computer Architecture
Internal Assessment - I Key

PART – A

   Answer all the questions                                       5 x 2 =10

1.               State the formula for power dynamics .(CO1)

2.               Define antidependence with example ?.(CO1)

3.               How to measure the dependability? (CO1)

4.               Define ALU.(CO2)

5.               What is bandwidth and latency ?(CO2)

             PART – B                                                       16 x 2 =32

6.  Give a brief explanation to avoid data dependence with dynamic scheduling. (CO2)16 

7. Give a brief explanation of trends in Power , Energy and Cost. (CO1) 16

8 Give a brief explanation to avoid control dependence with hardware Speculation. (CO2)16 

9. State and explain different generation of Computer (CO1) 16
                                                                    PART – C

10. Give a brief explanation about different dependences in computer architecture. (CO2)8

                                                                                                                                                                                        

                                                                                                                                         Maximum:50Marks

Part-A (2*5=10Marks)

1. Define ALU 

An arithmetic logic unit (ALU) is a digital circuit used to perform arithmetic and logic operations. It represents the fundamental building block of the central processing unit (CPU) of a computer. Modern CPUs contain very powerful and complex ALUs.

2. DefineAnti Dependence with examples

A data dependency in computer science is a situation in which a program statement (instruction) refers to the data of a preceding statement. In compiler theory, the technique used to discover data dependencies among statements (or instructions) is called dependence analysis

3. Define measure of dependability

Dependability is a measure of a system's availability, reliability, and its maintainability, and maintenance support performance, and, in some cases, other characteristics such as durability, safety and security.

4. What is the formula for power dynamics

Power = Capacitive Load * Voltage ^ 2 * Frequency Switched.

5. What is bandwidth and latency

 Latency (execution time): time to finish a fixed task • Throughput (bandwidth): number of tasks in fixed time • Different: exploit parallelism for throughput, not latency (e.g., bread) • Often contradictory (latency vs. throughput) • Will see many examples of this • Choose definition of performance that matches your goals • Scientific program: latency; web server: throughput?

Part-B (13*2=26 Marks)

6.     a)  Give a brief explanation to avoid data dependence with dynamic scheduling (16)
7. DIV.D F0,F2,F4
8. ADD.D F6,F0,F8
9. S.D F6,0(R1)
10. SUB.D F8,F10,F14
11. MULT.D F6,F10,F8

 Give a brief explanation to avoid control dependence with hardware Speculation(16)

7.  a)i)State and explain different generation of Computer (8)

S.N.	Generation & Description
1	First Generation The period of first generation: 1946-1959. Vacuum tube based.
2	Second Generation The period of second generation: 1959-1965. Transistor based.
3	Third Generation The period of third generation: 1965-1971. Integrated Circuit based.
4	Fourth Generation The period of fourth generation: 1971-1980. VLSI microprocessor based.
5	Fifth Generation The period of fifth generation: 1980-onwards. ULSI microprocessor based

 Give a brief explanation of trends in Power , Energy and Cost(16)

Capacitance (C): To first order (i.e., the architect’s point of view rather than the more detailed view of a circuit designer), aggregate load capacitance largely depends on the wire lengths of on-chip structures. Supply voltage (V): For decades, supply voltage (V or Vdd) has dropped steadily with each technology generation  Because of its direct quadratic influence on dynamic power, this has amazing leverage on power-aware design.

Activity factor (A): The activity factor is a fraction between 0 and 1 that refers to how often wires actually transition from 0 to 1 or 1 to 0. While the clock signal obviously switches at its full frequency, most other wires in the design have activity factors below 1. Strategies such as clock gating are used to save energy by reducing activity factors during a hardware unit’s idle periods

Clock frequency ( f ): The clock frequency has a fundamental and far-reaching impact on power dissipation. Not only does clock frequency directly influence power dissipation, but it also indirectly shapes power by its effect on supply voltage. Typically, maintaining higher clock frequencies may require (in part) maintaining a higher supply voltage

Dependencies between instructions

Q  Instructions often depend on each other in such a way that a particular instruction cannot be executed until a preceding instruction or even two or three preceding instructions have been executed.

•         1 Data dependencies

•         2 Control dependencies

3 Resource dependencies

Data dependencies

i1: load r1, a

i2: load r2, b

i3: load r3, r1, r2

i4: mul r1, r2, r4;

i5: div r1, r2, r4

mul r1, r2, r3

Control dependencies

jz   zproc

      :

zproc: load r1, x

      :

actual path of execution depends on the outcome of multiplication

impose dependencies on the logical subsequent instructions