Q1. Short answer: (8 points)

  1. Ideal pipeline CPI =1, name cases that the CPI is more than one.
  2. What are the differences between dynamic and static scheduling? And an example of each type.
  3. In a brief, discuss the ISA principles.
  4. The following techniques used to solve different problems.

a) Dynamic scheduling b) forwarding c) register rename.

Complete the following table by the appropriate technique to solve the following problems:

Solution / problem / Brief explain
RAW data hazard that cause pipeline to stall.
Hazard are not known at compile time and hazard cause problem
Number of register in the processor limited

Q2. Performance: (6 points)

A)Program contains from two parts…………………….. , what fraction of execution time, must the processing procedure take up in order for a 4 processor multi computer to achieve over all speed up 2.5?

B)Suppose you are designing cell phone. The real-time required to transmitting speech require that the phone execute 2 million instructions every 20 ms. Phone processor has CPI of 1, if the phone processor is clocked at 200 MHz, what can we do to increase the battery life of the phone.

Q3. Tomasulo algorithm: (11 points)

Double-issue processor, assuming the following:

  1. Issue and WB take one clock cycle.
  2. FU not pipelined (one instruction using FU).
  3. No forwarding between FU.
  4. Pipeline stage EX does both effective address and memory access (load/store), WB stage not need for store instruction (pipeline in the store instruction consists of the following stages: IS/EX/WB).
  5. Processor has 5 load buffer and 5 store buffer.
  6. If two instructions contend CDB in the same clock cycle, older instruction is awarded CDB.
  7. If two instructions contend for FU in the same clock cycle, older instruction is awarded FU.
  8. Instruction release their reservation station/buffer when they execution.
  9. Assuming the following table :

FU type / Time in EX / Number of FU / Number of reservation station
INT / 2 / 3 / 5
FP adder / 5 / 2 / 3
FP MUL / 10 / 2 / 3

Based on the following sequence of instructions complete the table:

instructions / FU type / ISSUE(IS) / EX / WB / Reason of stall
L.D F0,0(R1) / INT / 1 / 2-3 / 4 / ____
ADD.D F1,F0,F0
S.D F1,4(R1)
L.D F2,4(R1)
MUL.D F3,F2,F1
MUL.D F4,F1,F1
ADD.D F5,F4,F3
MUL.D F6,F1,F0
ADD.D F7,F4,F0
L.D F8,8(F7)
ADD.D F10,F1,F1
MUL.D F9,F1,F0