Introduction to CPU

Overview

• CPU stands for Central Processing Unit.
• Located on the motherboard, a rectangular object with multiple ports.
• Requires a heatsink for cooling due to high heat production.
• CPU is a critical component for data processing.

Types of Processors

• Modern computers may have multiple processors.
• Multi-core CPUs consist of several CPUs within one unit.
• Other processors include graphics and sound cards.

Components of CPU

1. Arithmetic Logic Unit (ALU)

   • Performs arithmetic and logical operations (addition, multiplication, etc.).
   • Evaluates conditions and determines truth values.

2. Control Unit (CU)

   • Oversees and coordinates the CPU operations.
   • Controls the flow of data and instructions within the CPU.

3. Registers

   • Small, fast storage locations within the CPU.
   • Used for immediate data storage and retrieval during operations.
   • Typically there are around 32 registers in a CPU.

Von Neumann Architecture

• Dominant architecture in modern computing.
• Originated in 1945, defines the structure of computer systems.
• Divides computers into four main components:
  1. Main memory (where registers fit)
  2. Control unit
  3. Processing unit
  4. Input devices
• Stored Program Concept: Instructions and data are stored together in binary form in memory.
• Von Neumann Bottleneck: Slow connections between memory and CPU can limit processing speed.

System Clock

• Provides timing signals for synchronization of circuits.
• Functions as a steady pulse (like a metronome) to regulate operations.
• The CPU operates at a faster clock speed than other components.
• Clock Speed: Important for determining how quickly a CPU can process instructions.

Fetch-Execute Cycle

1. Fetch Stage:

   • Retrieves instructions from memory.
   • Instructions are broken down into operator and operand.
   • Operator specifies the operation (e.g., addition), operand refers to the data involved.

2. Execute Stage:

   • Involves the ALU executing the instruction based on the decoded information.
   • Results are stored in registers or memory.
   • Involves read and write operations, depending on the instruction.

Conclusion

• The effectiveness of a CPU is determined by its clock speed and its ability to execute instructions efficiently.
• Understanding the components and functioning of a CPU is crucial for studying computer architecture.