Glossary
Terms and notation used in digital logic design and in this app.
| Minterm | An AND of every input variable, true or inverted, that is 1 for exactly one row of the truth table. |
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| Maxterm | An OR of every input variable that is 0 for exactly one row of the truth table. |
| SOP | Sum of products: an OR of AND terms, such as A·B + C. |
| POS | Product of sums: an AND of OR terms, such as (A+B)·C. |
| Prime implicant | A product term that cannot be simplified further without becoming wrong. |
| Don't care (X) | An input combination whose output does not matter, which the minimizer may treat as 0 or 1. |
| Fan-in / fan-out | The number of inputs a gate has, and the number of gate inputs one output drives. |
| Tri-state | An output that is 0, 1, or disconnected (Z). |
| Z | High impedance: nothing drives the wire. Shown in blue. |
| E | Error: drivers conflict, or an input is invalid. Shown in red. |
| Bus | A bundle of wires carrying a multi-bit value. |
| Latch / flip-flop | A one-bit memory. A flip-flop changes only on a clock edge. |
| Rising edge | The moment a clock goes from 0 to 1. |
| Gray code | A counting order in which consecutive values differ in one bit. |