# Constructing 4-to-16 Decoder from 4 2-4 Decoders

• goron
In summary, the conversation discusses the construction of a 4-to-16 line decoder using four 2-to-4 line decoders, each with two active-LOW enable inputs and the option to use two inverters. The conversation also mentions the construction of a 16-input multiplexer using four 4-input multiplexers, a 4-output demultiplexer, and an OR gate, with each smaller multiplexer having an active-HIGH enable input. The necessary inputs and outputs for the 16-input multiplexer are also mentioned. Despite initial difficulties, the individual was able to figure out the construction process with the help of others and encourages showing work for future assistance.

#### goron

1. Hi i basically need information on how to construct a 4-to-16 line decoder made of four 2-to-4 line decoders each of the smaller decoders is equipped with two active-LOW enable inputs and i am allowed to use 2 inverters in addition to the four decoders.

and also Show how to construct a 16-input multiplexer from four 4-input multiplexers,
a 4-output demultiplexer and an OR gate. each of the smaller multiplexers
is equipped with one (active-HIGH) enable, E. The 16-input MUX should have data
inputs I15 −I0, select inputs S3S2S1S0 and output Z.

I constructed a 4-16 decoder using five 2-4 decoders but that's not what i am after lol and not sure how to do this with four.

Thanks for any help

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i figured out the first question can anyone help with the second. The thing is there is only like 5 pages on this topic in my book and its very frustrating.

yay i figured it out (thanks for all the help :P) Glad to know this site doesn't care

To gogon..

hi gogon,
how to construct a 4-to-16 line decoder made of four 2-to-4 line decoders

Its not a matter of no one caring, its a matter of showing your work. Do realize that many HW helpers have FULL TIME JOBS and a FAMILY to worry about.

You would be able to find this circuit in elementary digital logic design textbooks.