The MC14521B consists of a chain of 24 flipflops with an input circuit that allows three modes of operation. The input will function as a crystal oscillator, an RC oscillator, or as an input buffer for an external oscillator. Each flipflop divides the frequency of the previous flipflop by two, consequently this part will count up to 224 = 16,777,216. The count advances on the negative going edge of the clock. The outputs of the last sevenstages are available for added flexibility.