Decoder (3-to-8)
Use the combinational 3-to-8 Decoder to convert a three-bit unsigned input into eight active-HIGH one-hot outputs for selection logic.
Overview
The 3-to-8 Decoder converts a three-bit unsigned input into eight active-HIGH one-hot outputs.
DigiSim Interface
| Direction | Pins | Behavior |
|---|---|---|
| Input | A, B, C | Binary code; A is the least-significant bit. |
| Output | Y0–Y7 | Active-HIGH one-hot result. |
Decode Table
There is no global enable input. Released inputs sample as LOW. Driven unknowns are evaluated by
binary completion; any output that differs among the possible selections is driven X rather than
released.
Simulation Boundary
The decoder produces selection logic only. It does not store or program data and does not model a particular memory decoder or IC package.
Learning Path
Prerequisites
Next Steps
Frequently Asked Questions
How do decoders work in memory systems?
Three address bits can select one of eight chip-enable lines, provided the surrounding circuit supplies any required global enable and correct active-level conversion. The decoder itself only produces one-hot logic.
What is the relationship between decoders and ROM?
A decoder maps each input code to one active output. A ROM combines address decoding with a stored output word, so the concepts are related, but a decoder is not itself a programmable memory.