The CPU Flashcards
(23 cards)
What does CPU stand for?
Central Processing Unit
What is the main function of the CPU?
It processes all of the data and instructions that make the system work.
Name three characteristics that affect the processing power of a CPU.
- Clock speed
- Number of cores
- Cache size
What does CPU architecture describe?
The main components of the CPU and how they interact with each other and with other parts of the computer system.
What is the role of the Control Unit (CU) in a CPU?
It is in overall control of the CPU and executes program instructions.
What is the fetch-decode-execute cycle?
The process followed by the Control Unit to execute program instructions.
What does the Arithmetic Logic Unit (ALU) do?
It performs calculations and logic operations.
List two types of operations performed by the ALU.
- Arithmetic operations (addition, subtraction)
- Logic operations (AND, OR, NOT)
What is the purpose of the cache in the CPU?
To store regularly used data for quick access.
How does the CPU prioritize data retrieval between cache and RAM?
The CPU checks the cache first; if the data is not there, it fetches it from RAM.
Fill in the blank: The CPU contains various _______ which temporarily hold tiny bits of data needed by the CPU.
registers
True or False: The cache has a higher capacity compared to RAM.
False
What is the main job of the Control Unit?
To control the flow of data inside and outside the CPU.
What is the function of the program counter?
To hold the address of the next instruction to be executed.
What is the Memory Address Register (MAR) used for?
To hold the address of the memory location to be accessed.
What does the Memory Data Register (MDR) hold?
The data inside the address that is being fetched from memory or written to memory
What are the steps of the Fetch Decode Execute cycle?
1.) PC is copied to the MAR
2.) The data inside the address that the MAR is pointing to is copied to the MDR
3.PC is incremented by 1
4.) CU decodes the instruction
5.) CU executes the decoded instruction
What does the Von Neumann architecture describe?
A system where the CPU runs programs stored in memory
This architecture was proposed by John Von Neumann in 1945 and is foundational to most modern computers.
What are the main components of the CPU in the Von Neumann architecture?
- Central Processing Unit (CPU) – The brain of the computer, responsible for executing instructions. It consists of:
Control Unit (CU) – Directs operations by fetching, decoding, and executing instructions.
Arithmetic Logic Unit (ALU) – Performs mathematical and logical operations. - Memory Unit – Stores both instructions and data in the same addressable memory space. This is typically RAM.
- Input/Output (I/O) Devices – Allow communication between the computer and the outside world, handling input (keyboard, mouse) and output (monitor, printer).
- Registers – Small, fast storage locations in the CPU that temporarily hold data and instructions.
These components work together to fetch, decode, and execute instructions.
What is the purpose of the accumulator?
Stores intermediate results of calculations in the ALU
The accumulator is essential for performing arithmetic and logic operations.
What are the steps involved in the Fetch part of the Fetch-Decode-Execute cycle?
- Copy memory address from PC to MAR
- Copy instruction from MAR to MDR
- Increment the PC
These steps prepare the CPU to execute the next instruction.
What occurs during the Execute Instruction phase?
The instruction is performed, which could include:
* Load data from memory
* Write data to memory
* Do a calculation or logic operation
* Change the address in the PC
* Halt the program
This phase is where the actual work dictated by the instruction is carried out.
What does the Control Unit (CU) do during the Decode Instruction phase?
Decodes the instruction in the MDR and prepares for the next step
The CU plays a crucial role in interpreting what the instruction means and what actions to take next.
