CPU

Describing the CPU

A CPU is a piece of hardware
It carries out instructions of a computer program
It does this by performing the following operations:
- Basic arithmetic
- Logical operations
- Control operations
- I/O operations
A CPU is divided up into $3$ different parts:
- Control unit (CU)
- Arithmetic logic unit (ALU)
- Registers
A CPU can only understand instructions in machine code
A CPU performs these calculations in binary code

Describing the CPU Cache and Registers

Data is either stored in:
- Memory
- Storage
- Cache
- Registers
A CPU cache is used for storing data used by the CPU
It reduces the average cost of reading and writing to memory
A CPU register is used for providing storage to the CPU
Reading from registers is even faster than reading from cache
Some registers have specific hardware functions that are read-only or write-only

Describing the Control Unit

The control unit is used for controlling the flow of data within the CPU
Input will come into the CPU via a bus
Then, output exits the CPU via a bus

Summarizing the Architecture of the CPU

ALU: Executes all calculation within the CPU
CU: Coordinates how data moves around the CPU
Registers: Allows the CPU to access data very quickly

Defining the Types of Registers

Program Counter
- Stores an address of the next and previous instruction in the RAM
Memory Address Register
- Stores an address of the current instruction in the RAM
Memory Data Register
- Stores the data sent to and received from RAM
Current Instruction Register
- Stores the actual instruction that is being decoded and executed
Accumulator
- Stores results of calculations

Decribing Components relevant to the CPU

Address Bus
- Carries the address of the instruction or data
Data Bus
- Carries data between the CPU and memory
Control Bus
- Sends control signals
- These could be memory read or write signals

References

Previous

5-Layer Network Model