Page 84 - Handout Digital Electronics

There are two ways to show this:

• Use the Boolean function and the input combination 10, that is substituting the 10 in the Boolean
expression, for example:
F = ABDo + ABD1 + ABD2 + ABD3 and substituting the values for A and B (10) in the
expression: 0.1.D0+0.0.D1+1.1.D2+1.0.D3
F = 0+0+D2+0, so F = D2.
• The second way or technique is to use the input combination 10 and propagate these two control
signals throughout the entire circuit. For example:

10.2 DE multiplexor
A DEMUX is the converse of a MUX. It has one data input line (D) and many outputs. Data
can be transferred from this single input to one of its many outputs. The application of
DEMUX is to send data from a single source to one of several destinations (see diagram).

Figure 21: Symbol of a 1 to 4 Demultiplexer

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