Building a Programmable Logic Controller with a PIC16F648A Microcontroller

 

11 Multiplexer Macros

 

As a standard combinational component, the multiplexer (MUX), allows the selection of one input signal among n signals, where n > 1, and is a power of two Select lines connected to the multiplexer determine which input signal is selected and passed to the output of the multiplexer As can be seen from Figure 11.1, in general, an n-to-1 multiplexer has n data input lines, m select lines where m = log2 n, i.e., 2^m = n, and one output line. Although not shown in Figure 11.1, in addition to the other inputs, the multiplexer may have an enable line, E, for enabling it. When the multiplexer is disabled with E set to 0 (for active high enable input E), no input signal is selected and passed to the output

In this chapter, the ...