The table shows the present state $Q(t)$, next state $Q(t{+}1)$, and a single control input for a flip-flop. Identify the flip-flop.
Show Hint
- T flip-flop
- D flip-flop
- SR flip-flop
- JK flip-flop
The Correct Option is A
Solution and Explanation
When Input $=0$: $Q(t{+}1)=Q(t)$ (0$\rightarrow$0, 1$\rightarrow$1) $\Rightarrow$ {hold}.
When Input $=1$: $Q(t{+}1)=\overline{Q(t)}$ (0$\rightarrow$1, 1$\rightarrow$0) $\Rightarrow$ {toggle}.
Step 2: Match to flip-flop types.
A T (toggle) flip-flop has one input $T$ with the rule \[ Q(t{+}1)= \begin{cases} Q(t), & T=0
\overline{Q(t)}, & T=1 \end{cases} \] which exactly matches the table.
A D FF would have $Q(t{+}1)=D$ independent of $Q(t)$ (not matching). SR and JK FFs require {two} inputs (not this case).
Final Answer: (A) T flip-flop
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