Leading zero detector $($LZD$)$ circuit is useful in many applications such as floating$-$point arithmetic. As the

name suggests, an LZD$-$k circuit outputs the number of leading zeros in a k$-$bit binary input. For example,

in an LZD$-4$ circuit the input is a $4-$bit binary number and the output is $3-$bit number denoting the number

of leading zeros:

If input is $1010$ output is $000,$ If input is $0010$ output is $010.$

If input is $0000$ output is $100,$ If input is $0101$ output is $001.$

If input is $1111$ output is $000,$ and so on $..$