1.1 Sys Architeture

Question 1

What are the two main internal components of a computer ?

Answer 1

CPU and RAM

Question 2

Name the ALUs functions

Answer 2

• arithmetic calculations
• making logical decisions

Question 3

What does the control unit do ?

Answer 3

• sends signals to control how data moves around the CPU

Question 4

What does the cache do ?

Answer 4

• provides fast access to frequently used instructions and data

Question 5

What do the registers do ?

Answer 5

• very specific individual things

Question 6

What are registers ?

Answer 6

Tiny , super fast pieces of onboard memory inside the CPU

Question 7

Name the 4 registers

Answer 7

• accumulator
• memory address register
• program counter
• memory data register

Question 8

Who designed computers with stored programs ?

Answer 8

John von Neumann

Question 9

What are the other three components in von Neumann architecture that aren’t the registers ?

Answer 9

Cache , control until and arithmetic logic unit

Question 10

What’s the key cycle that a computer does ?

Answer 10

Fetch decode execute

Question 11

What is the Von Neumann architecture?

Answer 11

The Von Neumann architecture consists of a Control Unit (CU), Arithmetic and Logic Unit (ALU), and Memory Unit (typically RAM).

Question 12

What is the stored-program concept?

Answer 12

It is based on the concept that both instruction data and program data are stored in the same memory in binary form.

Question 13

How can you identify data in memory?

Answer 13

There is no way to know if the pure binary held in memory is representing instructions or data simply by looking at it.

Question 14

What is the function of the Program Counter (PC)?

Answer 14

The Program Counter (PC) holds the address of the next instruction in memory.

Question 15

What does the Memory Address Register (MAR) do?

Answer 15

The Memory Address Register (MAR) holds the address of where data is to be fetched or stored.

Question 16

What is the role of the Memory Data Register (MDR)?

Answer 16

The Memory Data Register (MDR) holds the data fetched from, or to be written to memory.

Question 17

What does the Accumulator do?

Answer 17

The Accumulator holds the results of calculations.

Question 18

What is Clock Speed measured in?

Answer 18

Clock Speed is measured in Hz, which equals cycles per second.

Question 19

What regulates the CPU?

Answer 19

The CPU is regulated with clock signals.

Question 20

What is a clock cycle?

Answer 20

A clock cycle is the time between two clock signals.

Question 21

What can be executed per clock cycle?

Answer 21

A set number of instructions can be executed per clock cycle.

Question 22

What happens when clock cycles are faster?

Answer 22

The faster these cycles are, the more instructions can be executed per second.

Question 23

What is the purpose of cache?

Answer 23

Cache exists to speed up the operation of the fetch stage.

Question 24

How does cache size affect performance?

Answer 24

The larger the cache, the more instructions can be accessed faster.

Question 25

What is the trade-off in cache performance?

Answer 25

There is a trade-off between ‘cache latency’ (speed) and ‘hit rate’ (size).

Question 26

What are the levels of cache?

Answer 26

There are multiple levels of cache: L1, L2, and L3.

Question 27

What is L1 cache?

Answer 27

L1 cache is embedded in the CPU chip, and is the smallest and fastest.

Question 28

What are L2 and L3 caches?

Answer 28

L2 and L3 caches may be physically situated between the CPU and RAM, and are larger but slower.

Question 29

What is the purpose of L2 and L3 caches?

Answer 29

L2 and L3 caches exist to ‘back up’ L1 cache, where hits are the least likely.

Question 30

What is the function of multiple cores in a CPU?

Answer 30

Multiple cores allow multiple instructions to be executed simultaneously.

Question 31

What type of cache does each core have?

Answer 31

Each core will have at least their own L1 cache, and possibly L2 as well.

Question 32

What type of cache do all cores share?

Answer 32

All cores share a common L3 cache.

Question 33

What is the relationship between the number of cores and performance?

Answer 33

The number of cores can enhance performance by enabling the execution of multiple instructions at the same time.