Multilevel Viewpoint Of A Machine
Our computer is build on various layers:
• Software Layer (macro architecture)
• Instruction Set Architecture
• Hardware Layer microarchitecture
But a machine can have 5-6 levels:
Level 0 digital logic :
• The lowest level is called digital logic, which is a computer's real hardware. This is the building blocks for higher levels.
• We have objects called Gates, composed of transistors.
• In this only two logical values are present.
• Each gate has one or more digital input signals representing 0 or 1 and computes as output some function such as AND or OR. They can be used as registers or combined for memory.
• A signal between 0 and 1 volt represent one value (binary 0) and one between 2 and 5 represent the other value binary 1. Voltage outside date ranges are not permitted.