1.1.1 Structure and Function of the Processor Flashcards Preview

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Flashcards in 1.1.1 Structure and Function of the Processor Deck (23)
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1

Performance of the CPU

What three ways can the performance of the CPU be improved?

  • Increasing clock speed
  • Larger cache size
  • Having multiple cores

2

Performance of the CPU

How does increasing clock speed improve the performance of the CPU?

Control Unit uses a clock

Higher clock speed means more fetch-execute cycles per second, so more instructions can be carried out per second

More heat is produced, though therefore a cooling system is needed

3

Performance of the CPU

How does having a larger cache improve the performance of the CPU?

The MDR stores data in cache

Cache is a small piece of memory in the processor, which stores frequently used data, thus decreasing fetch time

Increasing cache size means more data can be stored closer than main memory

4

Performance of the CPU

How does having more cores improve the performance of the CPU?

Each core performs a fetch-execute cycle

Having more cores allows more instructions and cycles to be carried per second, allowing a greater processor speed

This would, however, require more complicated circuitry

5

Pipelining

Explain the process of pipelining

Multiple instructions are passed through the fetch-execute cycle at one time

As one instruction is being executed, the next one is being decoded

A third instruction is being fetched at the same time

All instructions more through the cycle, having multiple being processed at the same time

6

Pipelining

What are the limitations of pipelining?

Requires multiple cores to be a viable option

 

It will only work if the subsequent instruction can be predicted

If the wrong one is fetched, 'flushing the pipe' occurs, which when done too often can decrease the benefits of pipelining

 

'Flushing the pipe' is when the instructions are thrown away and the right one is fetched

7

Structure and function of the processor

What is the name and function of the CPU?

Central Processing Unit

Processes data and executes intructions

8

Structure and function of the processor

What general components are found inside the CPU?

ALU

CU

Registers (PC, MAR, MDR, CIR, ACC)

Buses (Address, Data, Control)

9

Structure and function of the processor

Which registers are found within the CPU?

PC (Program Counter)

MAR (Memory Address Register)

MDR (Memory Data Register)

CIR (Current Instruction Register)

ACC (Accumulator)

10

Structure and function of the processor

What is the name and function of the ALU?

Arithmetic and Logic Unit

Performs arithmetic and logical calculations

11

Structure and function of the processor

What is the name and function of the CU?

Control Unit

Sends signals to coordinate how the processor works

Controls the flow of data through the CPU, and to Main Memory

Decodes instructions fetched from memory

12

Structure and function of the processor

What are the roles of registers in the CPU?

Run at fast speeds to perform and control the fetch-decode-execute cycle

13

Structure and function of the processor

What is the name and function of the PC?

Program Counter

Stores the memory address of the next instruction

14

Structure and function of the processor

What is the name and function of the MAR?

Memory Address Register

Stores the memory address of the data or instruction that is to fetched or sent

The MAR will equal the PC if it is the location of an instruction, and the MDR will not equal the PC if it is the location of data

15

Structure and function of the processor

What is the name and function of the MDR?

Memory Data Register

Stores the data that is to be fetched or sent

16

Structure and function of the processor

What is the name and function of the CIR?

Current Instruction Register

Stores the instruction that is to be carried out

17

Structure and function of the processor

What is the name and function of the ACC?

Accumulator

Stores the results of the calculations performed by the ALU

18

Structure and function of the processor

What is the role of buses in the CPU?

Buses are communication channels between different components on the motherboard

19

Structure and function of the processor

What are the 3 common buses used on a motherboard?

Address bus

Data bus

Control bus

20

Structure and function of the processor

Describe how the address bus works

Unidirectional

Carries the address of data or instructions from the MDR on the CPU to Main Memory

21

Structure and function of the processor

Describe how the data bus works

Bidirectional

Carries data or instructions to and from Main Memory and the CPU

22

Structure and function of the processor

Describe how the control bus works

Bidirectional

Sends control signals between the components on the motherboard

Uses signals to specify which control bus line to use

23

Structure and function of the processor

Describe what control lines are, as well as 4 examples of signals that can be received

Signals are sent on control buses to specify an action to be performed

The control bus line to be used is the control line

 

Bus request

A device is requesting the use of a bus

 

Bus grant

The CPU granting access of a bus to a device, in response to a bus request

 

Interrupt request

A device resting access to the CPU

 

Clock

Synchronising operations