40 17BD is a 5-bit Johnson counter with 10 decoded output and CP, CR and INH inputs. Clock input cd40 17

The Schmitt trigger at the input has the function of pulse shaping, and there is no limit on the rising and falling time of the input clock pulse. When INH is low, the counter counts on the rising edge of the clock; Conversely, the counting function is invalid. When CR is high, the counter is cleared.