Understanding Multiplexers: Functionality and Applications
Multiplexers: Data Selection and Applications
A data multiplexer, or selector, is the electronic equivalent of a rotary switch. Input data is transferred through the contacts of the rotary switch. Similarly, with a multiplexer, input data is transferred through the selector circuit. The selection of data is achieved by mechanically rotating the rotor of the rotary switch. The data selector position is selected by applying the appropriate binary number for input data selection. A k data selector allows data to flow only from input to output, while the rotary switch allows data to flow in both directions. A data selector can be considered a rotary switch in dimension. Consider a two-channel multiplexer.
Procedure: National Development Circuit with Multiplexers
The steps for national development circuit combined with multiplexers are as follows:
- Problem definition
- Obtaining input variables
- Naming variables
- Truth tables
- Multiplexer selection
- Map set multiplexer
- Map creation
- Logical schema implementation in the laboratory
The design of three combinational circuits was carried out: A. Adder for two words of two bits each; B. Subtractor for two words of two bits; C. Full Adder.
Adder Design
For a three-bit adder or two words of two bits, the following is needed:
- Four input variables and one output
- For three variables, the selection of the multiplexer must analyze the most significant input variable for the multiplexer input, and the others are the selectors.
For subtractor two words of two bits each:
- Four input variables and three outputs are required.
- For this circuit design, an eight-channel multiplexer is used for the selectors.
For a three-bit adder or full adder:
- Three input variables and two outputs are required.
- For this circuit, a four-channel multiplexer having two selectors is used.
From this, the following conclusions can be drawn:
- The use of multiplexers in circuit design is an efficient tool to simplify their application.
- To determine the multiplexers to be used, it must be taken into account that k is the number of variables being handled, for establishing a number of selectors k possess. Depending on the number of selectors, the multiplexer circuit will be suited for use.
- The use of multiplexers, in addition to reducing the size of the circuitry, also significantly reduces their maintenance cost.
Concentrators (Hubs)
A hub is a hardware element that concentrates network traffic from multiple hosts and regenerates the signal. A hub has a certain number of ports (it has as many ports to connect computers to each other, usually 4, 8, 16, or 32). Its sole purpose is to recover the binary data entering a port and send it to other ports. As a repeater, a hub works on level one of the OSI model. It is for this reason that a repeater is sometimes called Multiplayer. The hub connects several computers together, sometimes arranged in a star pattern, which gives it its name (wheel hub in English). The Spanish translation is ‘dealer’ to illustrate the point where communication crosses.