IGCSE Computer Science Flashcards: Topic 3.1 - Computer Architecture

What is the CPU?

The CPU (Central Processing Unit) is the brain of a computer that processes data and runs programs.

What are the main parts of the CPU?

1. Control Unit (CU): Controls data flow in the CPU.

2. Arithmetic and Logic Unit (ALU): Does calculations and logic tasks.

3. Registers: Small, fast memory for temporary data storage.

4. Buses: Pathways to send data between components.

What is the Von Neumann Architecture?

A computer design where the CPU uses one memory to store both data and instructions.

What are the features of the Von Neumann Architecture?

1. The CPU handles all processing.

2. Programs and data share the same memory.

3. The CPU reads and writes directly to RAM.

4. Instructions are processed in order.

What does the ALU do?

It handles math (like addition) and logic (like comparing numbers).

What is the job of the Control Unit (CU)?

The CU tells all parts of the computer what to do and ensures tasks run smoothly.

What is the Fetch–Decode–Execute cycle?

1. Fetch: Get the instruction from memory.

2. Decode: Understand what the instruction means.

3. Execute: Perform the instruction.

What are registers?

Tiny memory spaces in the CPU that store data temporarily during tasks.

Name some registers and their functions.

1. CIR: Holds the current instruction.

2. ACC: Stores data during calculations.

3. MAR: Holds the address of data in memory.

4. MDR: Holds the data being read/written.

5. PC: Points to the next instruction.

What are system buses?

1. Address Bus: Sends memory addresses (one-way).

2. Data Bus: Sends and receives data (two-way).

3. Control Bus: Sends control signals to coordinate tasks.

What affects CPU performance?

1. Clock Speed: Faster speed = more instructions per second.

2. Bus Width: Wider buses = faster data transfer.

3. Cache Memory: Stores frequently used data for quick access.

4. Cores: More cores = multiple tasks at once.

What is an embedded system?

A computer system designed to do one specific job, like controlling a microwave or a car engine.

What are examples of embedded systems?

1. Cars: Control engine or safety features.

2. Home Appliances: Washing machines, microwaves.

3. Vending Machines: Dispense products automatically.

What are the advantages of embedded systems?

• Small and cheap.

• Use little power.

• Fast and efficient.

What are the disadvantages of embedded systems?

• Hard to fix or upgrade.

• Can be hacked if online.

• Must be replaced when outdated.

What are microcontrollers and microprocessors?

• Microcontrollers: Have CPU, memory, and peripherals on one chip (good for simple tasks).

• Microprocessors: Only have a CPU (need extra parts to work).

What is a System on Chip (SoC)?

A small chip that combines all hardware needed for a task in one place.

What is an instruction set?

The list of commands a CPU can understand and execute.