A demultiplexer, often abbreviated as DEMUX, is a digital logic circuit that takes a single input signal and distributes it to one of several output lines based on the control signals provided to the circuit. In essence, a demultiplexer performs the opposite function of a multiplexer (MUX), which combines multiple input signals onto a single output line.
The primary purpose of a demultiplexer is to route a single input signal to one of several possible outputs, depending on the binary code of the control signals. Demultiplexers are commonly used in various applications involving data distribution and signal routing. Here's how they work and how they're used in data distribution:
Demultiplexer Operation:
A demultiplexer typically has one input line, several control input lines (often referred to as selection lines), and multiple output lines. The number of control lines determines how many output lines the demultiplexer can have. The control lines determine which output line receives the input signal. The control signal is converted into a binary code, and each binary combination corresponds to a specific output line.
Data Distribution:
Demultiplexers are commonly used in scenarios where a single data source needs to be distributed to multiple destinations. For example, consider a scenario where you have a central processor sending data to different memory modules in a computer system, or a single communication channel sending data to multiple devices. In these cases, a demultiplexer can be used to direct the data from the central source to the appropriate destination based on the control signals.
Another example is in telecommunications, where a single high-speed data link from a main source is demultiplexed to distribute data to different users or endpoints, each connected to a different output line.
Address Decoding:
Demultiplexers are also commonly used in memory systems to decode memory addresses. The control lines of the demultiplexer are connected to the address lines from a processor, and the output lines are connected to individual memory cells. This way, when the processor sends an address to the memory system, the demultiplexer decodes the address and directs the data read or write operation to the specific memory cell corresponding to that address.
In summary, a demultiplexer is a digital logic circuit used to route a single input signal to one of multiple output lines based on control signals. It plays a crucial role in data distribution, addressing, and signal routing in various electronic systems, ensuring that data is properly directed to its intended destinations.