Advanced computer architecture 

UNIT I

1.      What are embedded computers?

             List their characteristics. Embedded computers are computers that are lodged into other devices where the presence of the computer is not immediately obvious. These devices range from everyday machine to handheld digital devices. They have a wide range of processing power and cost.  

2.      Define Response time and Throughput.

 Response time is the time between the start and the completion of the event. Also referred to as execution time or latency. Throughput is the total amount of work done in a given amount of time. 

3.      Mention the use of transaction processing benchmarks.

 It measures the ability of system to handle transactions, which consists of database accesses and updates. An airline reservation system and bank ATM are the examples of TP system. 

4.      State Amdalh’s law.

Amdalh’s law states that the performance improvement to be gained from using some faster mode of execution is limited by the fraction of time the faster mode can be used.

5.      What are toy benchmarks?

Toy benchmarks are typically between 10 and 100 lines of code and produce result the user already knows before running the toy program. E,g puzzle. 

6.      What is profile based static modeling?

In this technique, a dynamic execution profile of the program, which indicates how often each instruction is executed, is maintained. 

7.      Suppose that we are considering an enhancement to the processor of a server system used for web serving. The new CPU is 10 times faster on computation in the web serving application than the original processor. Assuming that the original CPU is busy with computation 40% of the time and is waiting for I/O 60% of the time. What is the overall speedup gained by incorporating the enhancement? 

Fraction enhanced = 0.4

Speedup enhanced = 10  Speedup

Overall  = 1/(0.6+0.4/10) =1/0.64 = 1.56 

8.      Explain the different types of locality.

Temporal locality, states that recently accessed items are likely to be accessed in the near future.

Spatial locality, says that items whose addresses are near one another tend to be referenced close together in time.

9.      Name the addressing modes used for signal processing?

 Modulo or circular addressing mode Bit reverse addressing mode. 

10.  Specify the CPU performance equation.

CPU time = Instruction Count x Clock cycle Time x cycles per instruction