Question

Decoder Implementation We are going to design a 4×16 line decoder. Unfortunately, you only found a 2×4 line decoder and a 3-8 line decoder. 1. Draw a block diagram of your design to build 4×16 decoder by using a 2×4 and a 3×8 decoder. Assign the input variables to the decoders and connect with AND gates properly in the diagram. Provide detailed schematic with pin numbers and gates.

Answer 1

The student's question pertains to designing a 4×16 decoder using a 2×4 decoder and a 3×8 decoder, connecting them with AND gates following specific logic related to the most and least significant bits.

Step-by-step explanation:

The student is asking for a block diagram design to build a 4×16 decoder using a 2×4 line decoder and a 3×8 line decoder. The implementation can be achieved by using the lower 2 bits of the input to drive the 2×4 decoder, and the upper 2 bits plus the enable/disable input to drive the 3×8 decoder.

First, the outputs of the 2×4 decoder will each be connected to 4 AND gates. Each AND gate will also be connected to one of the outputs from the 3×8 decoder. The two most significant bits of the input will be connected to the selection inputs of the 3×8 decoder, while the 2×4 decoder will be permanently enabled. Assuming the enable input on the 3×8 decoder is active low, it will also be connected to the output of the 2×4 decoder, essentially enabling the 3×8 decoder when the 2×4 decoder outputs a high signal, which denotes valid input.

It is worth noting that each output from the 2×4 decoder will connect to a set of AND gates operated by different outputs of the 3×8 decoder, facilitating the generation of the 16 outputs required by the final 4×16 decoder.