INTRODUCTION

Question 1

What is computer architecture?

Answer 1

attributes of a system that have a direct impact on the logical execution of a program.
It’s about what a computer does eg the multiply instruction

Question 2

Give examples of some aspects of computer architecture

Answer 2

• the instruction set
• the number of bits used to represent various data types
• I/O mechanisms
• memory addressing techniques

Question 3

What is computer organization

Answer 3

operational units and their interconnections that realize the architectural specifications.

Deals with how features are implemented e.g. Is there a hardware multiply unit or is it done by repeated addition?

Question 4

Give examples of some aspects of computer organization

Answer 4

Control signals
interfaces
memory technology.

Question 5

How does the organization and architecture differ across different versions from the same computer?

Answer 5

Different versions have the same basic architecture eg
All Intel x86 family share the same basic architecture
The IBM System/370 family share the same basic architecture

However, Organization differs between different versions

Question 6

What is the benefit of having the same basic architecture across different versions from the same family

Answer 6

This gives code compatibility (At least backwards)

Question 7

What is a hierarchical system?

Answer 7

A set of interrelated subsystem, each of the later, in turn, hierarchical in structure until we reach some lowest level of elementary subsystem.

Question 8

What is structure?

Answer 8

Structure is the way in which components relate to each other.

Question 9

What is function?

Answer 9

Function is the operation of individual components as part of the structure

Question 10

What are the different functions in a computer?

Answer 10

• Data processing: Computer must be able to process data which may take a wide variety of forms and the range of processing.
• Data storage: Computer stores data either temporarily or permanently.
• Data movement: Computer must be able to move data between itself and the outside world. (I/O systems)
• Control: There must be a control of the above three functions.

Question 11

Draw the function view of a computer and illustrate the following scenarios:
Data movement
Storage
Processing from/to the storage
Processing from storage to i/o

Answer 11

*See the notes for a pic

Question 12

What are the main structural components of the computer

Answer 12

• Central processing unit (CPU)
• Main memory
• I / O
• System interconnections

Question 13

What are the CPU structural components:

Answer 13

• Control unit
• Arithmetic and logic unit (ALU)
• Registers
• CPU interconnections

Question 14

List ways to increase microprocessor speed

Answer 14

Pipelining
Having on-board L1 & L2 cache
Branch prediction
Data Flow analysis
Speculative execution
Adding new circuits, and the speed boost that comes from reducing the distances between them

Question 15

What is branch prediction?

Answer 15

The processor looks ahead in the instruction code fetched from memory and predicts which branches, or group of instructions are likely to be processed next.

Question 16

What is data flow analysis?

Answer 16

The processor analyzes which instructions are dependent on each other’s results, or data, to create an optimized schedule of instructions to prevent delay.

Question 17

What is speculative execution?

Answer 17

Using branch prediction and data flow analysis, some processors speculatively execute instructions ahead of their actual appearance in the program execution, holding the results in temporary locations.

Question 18

Describe performance mismatch

Answer 18

while processor speed and memory capacity have grown rapidly, the speed with which data can be transferred between main memory and the processor has lagged badly

Question 19

What are some solutions to improve performance?

Answer 19

• Increase the number of bits that are retrieved at one time by making DRAMs “wider” rather than “deeper” and by using wide bus data paths.
• Change the DRAM interface to make it more efficient by including a cache7 or other buffering scheme on the DRAM chip.
• Reduce the frequency of memory access by incorporating increasingly complex and efficient cache structures between the processor and main memory.
• Increase the interconnect bandwidth between processors and memory by using higher speed buses and by using a hierarchy of buses to buffer and structure data flow.

Question 20

How is programming a system better than hardwiring it?

Answer 20

Hardwired systems are inflexible. General purpose hardware can do different tasks, given correct control signals. Instead of re-wiring, supply a new set of control signals

Question 21

Draw a diagram to show the difference between programing in hardware and programing is software

Answer 21

*See notes for picture