# Digital electronics

Introduction — Simplicity, abstraction, discipline, intent

### Logic

Logic — basic gates AND OR NOT XOR

Universal gates — your first logic puzzle

DeMorgan’s theorem — a logic superpower

DeMorgan’s theorem for basic gates

Assertion — high/low, on/off, active, asserted

### Simplification

- Karnaugh map (Car’-naw) - graphical simplification

### Bits as commands

### Bits as symbols

- $2^n$
- bytes
- distance
- Gray code - distance 1 code

### Bits as numbers

- Binary numbers, octal, hexadecimal
- Addition
- Subtraction

### Bits as memory

- Digital memory - cross-coupled inverters
- SR flip-flop with NAND and NOR
- Flip-flops — D, T, JK

### Counting

- Introduction
- Shift register
- Johnson counter
- Binary counter
- Carry chains
- Linear-feedback shift register