Digital Systems
- Digital systems are designed to store, process, and communicate information in digital form.
- They use discrete values, such as binary digits (0s and 1s), to represent data.
Note
Digital systems are the backbone of modern technology, enabling everything from smartphones to complex industrial machinery.
Binary Digits
Definition
Binary Digit
A binary digit has either a value of 0 or 1. These values correspond to on and off signals in electronic circuits.
Analogy
Think of binary digits like a light switch: 0 represents the switch being off, and 1 represents it being on.
Logic Gates
Definition
Logic Gates
A digital device that performs a Boolean function, controlling whether an input signal passes through to the output based on logical rules (e.g., AND, OR, NOT).
Note
Logic gates are the fundamental building blocks of digital circuits, enabling complex computations and decision-making processes.
How Logic Gates Work
- Logic gates use transistors to control the flow of electricity.
- Transistors act as switches, turning on or off based on the input signals.
- The combination of these switches determines the gate's output.
Analogy
- Consider a logic gate as a series of water pipes with valves.
- The transistors are the valves, controlling the flow of water (electricity) based on the input conditions.
Types of Logic Gates
- AND Gate
- Outputs 1 only if all inputs are 1.
- Symbol: D-shaped with a flat side for inputs and a curved side for output.
- NOT Gate
- Inverts the input: 0 becomes 1, and 1 becomes 0.
- Symbol: Triangle with a circle at the output.
- OR Gate
- Outputs 1 if at least one input is 1.
- Symbol: Curved shape with a pointed output.
- XOR Gate
- Outputs 1 if exactly one input is 1.
- Symbol: OR gate with an extra curved line on the input side.
- NOR Gate
- Outputs 0 if at least one input is 1.
- Symbol: OR gate with a circle at the output.
- XNOR Gate
- Outputs 1 if inputs are equal.
- Symbol: XOR gate with a circle at the output.
Tip
- When analyzing logic gates, always start by identifying the type of gate and its inputs.
- This will help you predict the output accurately.
Advantages & Disadvantages of Digital Systems
| Advantages | Disadvantages |
|---|---|
| Noise Resistance: Binary signals are less affected by interference | Loss of Detail: Quantization can lead to a loss of subtle information |
| Easy Storage and Processing: Data can be compressed, encrypted, and transmitted efficiently | Complexity: Requires conversion from analogue to digital and vice versa |
