Question

Design a 4-to-16 line Decoder by using the two 3*8 decoder-line decoders. The 3-to-8 line decoders have an enable input ( '1' =enabled) and the designed 4-to-16 line decoder does not have an enable. Name the inputs A0........A3 and the outputs D0.......D15.​

Answer 1

- Connect A0, A1 and A2 to the inputs of the two 3-to-8 decoders

- Connect A3 to the enable input of the first 3-to-8

- Connect A3 also to an inverter, and the output of that inverter to the enable input of the second 3-to-8

- D0 to D7 of the first 3-to-8 is D0 to D7 of your 4-to-16

- D0 to D7 of the second 3-to-8 is D8 to D15 of your 4-to-16