A register that goes through a prescribed sequence of states upon the application of input pulses is called a counter. The input pulses may be clock pulses, or they may originate from some external source and may occur at a fixed interval of time or at random. The sequence of states may follow the binary number sequence or any other sequence of states. A counter that follows the binary number sequence is called a binary counter . An
n ‐bit binary counter consists of n flip‐flops and can count in binary from 0 through 2n - 1.
