# Tag: Combinational logic

• ## 9.8 Using Multiple Combinational Circuits

As an example of using several circuits together, we are going to make a device that will have 16 inputs, representing a four digit number, to a four digit 7-segment display but using just one binary-to-7-segment encoder. First, the overall architecture of our circuit provides what looks like our the description provided. Follow this circuit…

• ## 9.7 Multiplexers

A multiplexer, abbreviated mux, is a device that has multiple inputs and one output. The schematic symbol for multiplexers is The truth table for a 2-to-1 multiplexer is Using a 1-to-2 decoder as part of the circuit, we can express this circuit easily. Multiplexers can also be expanded with the same naming conventions as demultiplexers.…

• ## 9.6 Demultiplexers

A demultiplexer, sometimes abbreviated dmux, is a circuit that has one input and more than one output. It is used when a circuit wishes to send a signal to one of many devices. This description sounds similar to the description given for a decoder, but a decoder is used to select among many devices while…

• ## 9.5 Encoder

What is an Encoder? An encoder is a circuit that changes a set of signals into a code. Let’s begin making a 2-to-1 line encoder truth table by reversing the 1-to-2 decoder truth table. This truth table is a little short. A complete truth table would be One question we need to answer is what…

• ## 9.4 Decoder

A decoder is a circuit that changes a code into a set of signals. It is called a decoder because it does the reverse of encoding, but we will begin our study of encoders and decoders with decoders because they are simpler to design. Types of Decoders Line Decoder A common type of decoder is…