CPU - Processor Components

Main Functions:

1. Fetch Instruction from instruction Memory
2. Read Register Operands
3. Compute with ALU
4. Access data memory for load / store
5. Store the result of computation or loaded data into destination register
6. Update Program Counter

Datapath Components :

Simply: Handles and manipulates the data as instructed by the program being executed.

• Registers → Store the data being used by CPU. The ALU can access quickly.
• ALU → Performs operations on the data in registers
• Multiplexor (Mux) → Decide which data should be sent where
• Buses (Circuits) → The highways of data transfers, connecting the CPU to different parts of the computer
• Program Counter → Seen in (MIPS) Assembly Language.
• Instruction Register
• Data Memory

Control Path:

• Control Unit →
  • Retrieves instructions from DRAM
  • Decodes the Instruction
  • Does a lot more lol
• Circuit Clock
• Instruction decoder
• Instruction Decoder
• Status Flags or Condition Codes
• Finite State Machine

Diagram:

Processor Speed:

Important Theorem

$\text{Execution Time}=\frac{\text{Instruction Count}\times \text{Cycle Time}}{\text{Clock Frequency}}$