CPU Flashcards
What is a CPU?
Central Processing Unit
What is the purpose of a CPU?
Process data and instructions
To control the rest of the computer system
What is the process of a CPU?
Receives instructions from an input.
Processed by the CPU.
Results are sent to an output or transferred to a secondary storage.
Data is held in primary storage while it is being processed.
Input and output examples
Input- Keyboard, mouse, camera
Output- Monitor, printer, speaker
Common CPU parts
Control unit.
Arithmetic logic unit.
Registers.
Cache.
Buses.
Clock.
What are the key elements of a Von Neumann architecture?
Data and instructions are both stored as binary digits.
Data and instructions are both stored in primary storage.
Instructions are fetched from memory one at a time and in order (serially).
The processor decides and executes an instruction, before cycling around to fetch the next instruction.
The cycle continues until no more instructions are available.
What are the seven stages of fetch-decode-execute cycle?
The memory address held in the program counter is copied into the memory address register.
The address in the program counter is incremented by one. The program counter now holds the address of the next instruction to be fetched.
The processor sends a signal along the address bus to the memory address held in the memory address register.
The instruction or data held in that memory address is sent along the data bus to the memory data register.
The instruction or data held in the memory address register is copied into the current instruction register.
The instruction or data held in the current instruction register is decoded and then executed. Results of processing are stored in the accumulator.
The cycle returns to step one.
What affects the performance of a CPU?
Clock speed.
Cache size.
Number of cores.
What is clock speed?
Number of pulses the central processing units clock generates per second. Hz.
What is Cache?
Small amount of high speed random access memory built directly within the processor.
Is is used to temporarily hold data and instructions that the processor is likely to reuse.
What is a core?
A processing unit within a CPU is known as a core.
Each core is capable of fetching,decoding and executing its own instructions.
What are the four types of primary storage?
Read only memory (ROM)
Random access memory (RAM)
Flash memory
Cache memory
What is volatile?
Example
Volatile memory loses its contents when power is lost.
RAM
What is non-volatile?
Example
Keeps its contents even when the computer is switched off.
ROM
What is a graphics processing unit?
Microprocessor that performs calculations to produce high-quality graphic images on a screen.
