1.1 System Architecture Flashcards Preview

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Flashcards in 1.1 System Architecture Deck (19)
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1
Q

What is a CPU?

A

Central Processing Unit made of silicon and has billion of switches inside.
Carries out all the commands and processes information.

2
Q

What is clock speed?

A

Measured in Hz and corresponds with how many FDE cycles the CPU can do in a second:
4GHz= 4 billion FDE cycles per second.

3
Q

What is cache?

A

Storage location faster than RAM.
Stores commonly used instructions (don’t have to go to CPU to FDE).
Volatile and small.
Really expensive.

4
Q

How does the number of cores affect CPU speed?

A

Cores act as another CPU:
More cores = more instructions carried out.
Only useful when the applications are programmed to handle it.

5
Q

What does the PC do?

A

Stores the address of the next instruction to be run

Increments by 1 each time

6
Q

What does the ACC do?

A

Holds the data (number) that you are currently working on / result from ALU.

7
Q

What does the MAR do?

A

Contents of the PC are copied here.

Stores the address where the next data will be fetched from

8
Q

What does the MDR do?

A

Stores data / instructions being brought back from the RAM.

9
Q

What does the CIR do?

A

The instructions / data in the MDR are copied here.

10
Q

What does the data bus do?

A

Carries data around (can go both ways).

11
Q

What does the address bus do?

A

Carries around addresses (can only go one way).

12
Q

What does the control bus do?

A

Sends signals to the RAM to either re-write or bring the data back.

13
Q

What does the Arithmetic Logic Unit (ALU) do?

A

Does the arithmetic (mathematical) and logic calculations within the computer.

14
Q

What does the Control Unit (CU) do?

A

Manages the data:
Controls where data goes and monitors the flow of data.
Executes instructions.
Sends control signals between the different internal components.

15
Q

What is Von Neumann architecture?

A

Data + instructions are stored in the same RAM location.

FDE cycle is then used to FDE the instructions

16
Q

What is an embedded system?

A

Computer system inside a larger computer system.

17
Q

What happens in Fetch?

A

1) Memory address is copied from PC –> MAR.

2) Copy instruction stored in MAR –> MDR.

18
Q

What happens in Decode?

A

1) Instruction in the MDR is decoded by the CU.

2) CU may then prepare for the next step e.g. loading values into the MAR or MDR.

19
Q

What happens in Execute?

A

1) Instruction is executed.
2) PC is incremented so the CPU can now execute the next instruction in memory.
3) Before a new instruction is incremented, CPU checks for interrupts.