A simple encoder circuit canis receive[[one-hot]] ato singlebinary activeconverter. inputThat outis, if there are of 2<sup>''n''</sup> input lines generateat athe input, whereas only one of them is in 1, binary code of this 'hot' line is produced a on the ''n'' parallel'-bit output lines.
For example a single bit 4 to 2 encoder takes in 4 bits and outputs 2 bits. The illustrated gate level example implements the simple encoder defined by the truth table, but it MUST be understood that for all the non-explicitly defined input combinations (i.e. inputs containing 0, 2, 3, or 4 bits) the outputs are treated as don't cares. It Thusmakes thisno implementationsense isto uselessinfer as athe priority encoder and only useful as a simple encoder if some previousinput circuit guarantees that there is one and only one bit high in the input or if it is understood that non-single-active-inputs will produce garbage encodings.
