CMPSC 64 Lecture Notes - Lecture 14: Sequential Logic, Multiplexer, Truth Table
Document Summary
A logical selector: select either input a or input b to be the output. Mux truth table and logic circuit 1-bit mux. Muxes can have i/o that are multiple bits. 2:1 (a0 a1) (b0 b1) -- sel -- 00 01. 6:1 a b c d e f -- sel -- o. Make it possible for several signals to share one resource. Very commonly used in data communication lines. Data lines -> mux -> shared data line ("trunk") -> demux -> data lines. N: how "wide" the input is (# of input bits, min 1) M: how many inputs to the mux (min 2) The select input (s) has to be able to select 1 out of m inputs. M = 2 --> s >= 1 bit. M = 3 --> s >= 2 bits. M = 4 --> s >= 2 bits. M = 5 --> s >= 3 bits. Generally, we can do 2#: 1 muxes from 2:1 muxes.
