If computer architecture is a view of the whole design with the
important characteristics visible to programmer, computer organization
is how features are implemented with the specific building blocks
visible to designer, such as control signals, interfaces,
memory technology, etc. Computer architecture and organization are
closely related, though not exactly the same.
A stored program computer has the following basic units:
- Processor -- center for manipulation and control
- Memory -- storage for instructions and data for currently executing
programs
- I/O system -- controller which communicate with "external" devices:
secondary memory, display devices, networks
- Data-path & control -- collection of parallel wires, transmits
data, instructions, or control signal
Computer organization defines the ways in which these components
are interconnected and controlled. It is the capabilities and performance
characteristics of those principal functional units. Architecture can have
a number of organizational implementations, and organization differs
between different versions. Such, all Intel x86 families share the same
basic architecture, and IBM system/370 family share their basic
architecture.