Synchronous $3-$digit counters based on T flip$-$flops. $1)$ Write down the input logic functions for three T flip$-$flops for $3-$digit synchronous up$-$counter. $2)$ Draw the schematic of a synchronous $3-$digit up$-$counter, using T flip$-$flops. $3)$ Draw the schematic of a hybrid synchronous $3-$digit up counter with an En signal. The counter pauses its counting when En$=0.$