Week 2 - Hardware Architecture And The Processor

Question 1

What is The Most Basic Level Of Storage In A Computer?

Answer 1

Bits (1’s and 0’s Or Binary Digits)

Question 2

What is Primary Memory? What does it store? What is it made of?

Answer 2

Volatile memory such as RAM. It handles program data and communicates with the processor. It is made of circuits of chips.

Question 3

How does RAM work

Answer 3

Electric Charge flows through capacitors. Capacitors with a charge on them are 1’s, capacitors with no charge are 0’s.

Question 4

What type of RAM must be refreshed to maintain its charge?

Answer 4

DRAM (Dynamic RAM)

Question 5

What type of RAM doesn’t need to be refreshed to maintain its charge? Why?

Answer 5

SRAM (Static RAM), it uses areas of high and low voltage to determine charge, so no refreshing is needed.

Question 6

What two components is the CPU made up of?

Answer 6

1. The Control Unit

2. The Arithmetic Logic Unit (ALU)

Question 7

1. How does a CD/DVD drive write data?

2. How does the Hard Drive store data?

Answer 7

1. A laser etches pits into the surface of the disc which represents the 1’s and 0’s.
2. Magnets are used to create areas of north south magnetic polarity. These represent 1’s and 0’s.

Question 8

A bit isn’t very useful on its own!

1. What is the other, more useful unit of storage is used?
2. How many bits are used to make up this Unit?
3. What is a word?
4. How many ‘Useful Units’ are in a 64 bit word?

Answer 8

1. A byte!
2. 8 bits make up a byte!
3. A word is the maximum number of bits the processor can handle at once, and thus, the largest number of bits that can be stored per memory address!
4. 8Bytes! (8bits x 8Bytes = x64)

Question 9

What is assigned to a byte in order for it to be located by the processor?

Answer 9

An address

Question 10

A byte can represent 4 types of data. What are they?:

Answer 10

• A whole number
• A negative, whole number.
• A character.
• A number with a fractional part.

Question 11

The “Stored Program Concept” represents how the CPU interacts with program data and memory.

1. What are the two different architectures that relate to the “Stored Program Concept”
2. What are the three main differences between the two architectures?

Answer 11

1. Von Neumann and Harvard
2. • Von Neumann stores program memory and data memory together in a cache. Harvard stores it separately in two caches.
   • VN uses an 8 bit bus to transfer data to and from the CPU. HVD uses a 14 bit bus (program memory) and an 8 bit bus (data memory)
   • VN cannot both read and wrote data at the same time. HVD can. HVD has two separate memory address spaces for each cache

Question 12

What function does the ALU perform?

Answer 12

It performs the Arithmetic and Logic Operations on data.

Question 13

1. What is the purpose of the Control Unit?

2. What does the Control Unit use to achieve this?

Answer 13

1. To synchronise and manage processes.

2. A clock

Question 14

1. What data type does the ALU perform its operations on?

2. Where does the ALU take operands (data that needs to be processed) from, and store outputs in?

Answer 14

1. Words

2. Registers

Question 15

Define a register:

Answer 15

“A small set of high speed memory found in the cpu.”

Question 16

The number of registers is limited. How are processes managed to mitigate this issue?

Answer 16

Data is moved continually between the register and memory to free up space for new processes.

Question 17

What can a register hold?

Answer 17

• Instructions
• Memory Addresses
• Data

Question 18

What is a general register?

Answer 18

A general register is a register which holds an intermediate value used for a process or algorithm.

Question 19

What cycle is controlled by the Control Unit?

Answer 19

The “Fetch Execute” cycle

Question 20

The Control Unit contains a special register which contains the memory address of the next executable instruction.

What is this called?

Answer 20

The “Program Count”

Question 21

What are the six steps that occur in the fetch execute cycle?:

Answer 21

1. Fetch the next instruction from the memory address pointed at by the PC.
2. Increment the PC to point to the next instruction in memory.
3. Decode The Instruction.
4. Fetch data from memory if needed.
5. Execute the instructions.
6. Store results to memory if needed.

Question 22

1. ) What is Pipelining?
2. ) Why is pipelining used?
3. ) What is the more technical term for computing instructions in parallel?

Answer 22

1. ) Processing each fetch, decode, execute and store process concurrently and in parallel.
2. ) It speeds up the fetch execute cycle as all steps occur simultaneously, not sequentially.
3. ) Instruction-level Parallelism.

Question 23

1. ) CISC has a ………… and more feature rich instruction set than RISC.
2. ) CISC has a ……….. clock speed than RISC
3. ) CISC has ……….. general purpose registers.
4. ) CISC uses ………. or ……….. Pipelining.
5. ) CISC is usually used in ………. and Mainframes.

Answer 23

1. ) Larger
2. ) Slower
3. ) Fewer
4. ) Limited or No
5. ) PC’s

Question 24

1. ) RISC processors use …………., ………… simplified instruction sets.
2. ) RISC processors have a ………. clock speed.
3. ) RISC has ……….. general purpose registers.
4. ) RISC uses ………. Pipelining (Instruction Level Paralellism)
5. ) RISC is used mainly in ……….. devices.

Answer 24

1. ) Smaller, simplifies.
2. ) Faster.
3. ) More.
4. ) Extensively.
5. ) Mobile.