Digital Systems: Principles and Design

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Digital Systems

Logic design and implement a Boolean function F = P M (1, 7, 9, 13) by using a decoder.

Solution

Since highest minterm is M(13), a four bit input based decoder is needed. Since the

maxterms implement the Boolean function, we need a decoder with active 0 (inactive state

= 1) output. Figure 10.18 shows the implementation.

Example 10.9

FIGURE 10.18 An implementation of a Boolean function F ’ = PM (1, 7, 9, 13) by using a decoder.

Design a circuit for a decoder with three inputs and active 0 and 1 outputs and implement the

decoder circuit by NANDs alone. How will you extend the circuit for four inputs.

Solution

Since a decoder ...