MUX, DEMUX, encoder, decoder — visualise data selection and routing circuits
Combinational blocks are standard circuits whose output depends only on current inputs. They are the building blocks of data paths, address decoders, bus arbiters, and ALUs.
A 2ⁿ-to-1 MUX selects one of 2ⁿ data inputs using n select lines. Any combinational Boolean function can be implemented with a single MUX by connecting the truth-table output values to the data inputs.
A binary decoder asserts exactly one of its 2ⁿ outputs for each input combination — used in memory address decoding. A priority encoder converts 2ⁿ one-hot inputs to an n-bit code, resolving simultaneous active inputs by priority.