A binary decoder serves to decode binary information by converting the input bit pattern into the output pattern of our choice. For example, the following figure shows a 2-4 binary decoder that converts 2 bits of input into a 4-bit output. The important thing to notice is that in the 4-bit output, only one bit is 1, or high.
The applications of decoders are limitless, but we can imagine that this decoder can be used to activate one of 4 devices by sending it a bit pulse.
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