Computer organization

Lecture #4: Hardware architecture

Computer organization

The von Neumann machine model the traditional model of computer architecture is the von Neumann machine, which has five major components:
• the input unit
• the output unit
• the arithmetic/logic unit
• the control unit
• the memory unit

Lecture #4: Hardware architecture

Computer organization

The von Neumann machine model

The system bus model in the system bus model, a more modern account, several components are consolidated and interconnection is made by way of a bus

Lecture #4: Hardware architecture

Computer organization

The von Neumann machine model

The system bus model

Structure of the system bus • a bus is a shared pathway, usually comprised of a collection of "wires," along which data can be transferred
• the bus may be organized into several parts which perform different functions (e.g., data bus, address bus, etc.)

Lecture #4: Hardware architecture

Computer organization

The von Neumann machine model

The system bus model

Structure of the system bus

Busses and bandwidth • each individual bus component has a "width," which is the number of wires it contains, and thus the number of (bit) signals it can send simultaneously
• bandwidth = total amount of data transmitted per unit of time (cycle rate x width of data path)
• cycle rates are measured in Hz (cycles per second), though for modern computers we usually use KHz, MHz or GHz (thousands, millions or billions of cycles per second)

	The von Neumann machine model
	The system bus model in the system bus model, a more modern account, several components are consolidated and interconnection is made by way of a bus

	The von Neumann machine model
	The system bus model
	Structure of the system bus • a bus is a shared pathway, usually comprised of a collection of "wires," along which data can be transferred • the bus may be organized into several parts which perform different functions (e.g., data bus, address bus, etc.)

	The von Neumann machine model
	The system bus model
	Structure of the system bus
	Busses and bandwidth • each individual bus component has a "width," which is the number of wires it contains, and thus the number of (bit) signals it can send simultaneously • bandwidth = total amount of data transmitted per unit of time (cycle rate x width of data path) • cycle rates are measured in Hz (cycles per second), though for modern computers we usually use KHz, MHz or GHz (thousands, millions or billions of cycles per second)