Why Do We Use Multiplexers in Digital Systems?

[RMZ]

I don't understand what the point of a multiplexer is. I see the purpose of a selector circuit and a decoder, as an appropriate address will cause a unique gate to output a logic high, but I don't see the point of "OR"ing them together to get a single one or zero at the end. Please help

 

[phinds]

A mux simply allows you to do a controlled select of one of several signals.

Suppose for example that you have a recording device but only one path to it (very common in, for example, tape or disk data recording). A mux allows you to record each of numerous signals, sampled one at a time, and then repeat that sequence over and over. Thus you will hear the phrase "time division multiplexor".

 

[RMZ]

So does that mean that in:
(D1 and D2 mean AND gate1 and 2, while d1 and d2 mean AND gate 1 and 2 in the decoder.)
A--------D1---OR
B--------D2---the same OR
d1-----D1
d2-----D2

if I input an address that will "enable" D2 to change the OR gate's output, as I pulse a logic high/low through B the MUX will mimic the output of D2?

 

[phinds]

I have no idea what you are talking about. Draw a box with 4 inputs and one output. Label the inputs A, B, C, D and label the output A OR B OR C OR D (but NOT logically ORed together, just selected as one of the four)

Of course, you also have to have 2 control line inputs to tell the mux which of the 4 inputs to pick for the output.

 

[rezeew]

A multiplexer, or MUX, is a fundamental component in digital systems that allows for the selection and routing of multiple inputs to a single output. It is a versatile and efficient way to manage data flow and control signals within a system.

The main purpose of a MUX is to simplify the design and reduce the number of components needed in a system. Instead of having multiple selector circuits and decoders, a MUX combines these functions into one device. This not only saves space, but also reduces the complexity and potential for errors in the system.

Furthermore, a MUX can be used to enable different inputs at different times, allowing for efficient use of resources. For example, in a computer system, a MUX can be used to select between different memory addresses, enabling the CPU to access data from different locations in the memory at different times.

In addition, MUXes are used in various applications such as data transmission, signal processing, and communication systems. They are essential in modern technologies such as smartphones, computers, and networking equipment.

In summary, the point of a MUX is to simplify and streamline the design of digital systems, enable efficient use of resources, and facilitate data flow and control. It is a crucial component in modern technology and plays a significant role in the functioning of various devices and systems. I hope this helps clarify the purpose and importance of a MUX.