The CD4017BC is a 5-stage divide-by-10 Johnson counter with 10 decoded outputs and a carry out bit. This counter is cleared to its zero by a logical "1" on its reset line. This counter is advanced on the positive edge of the clock signal when the clock enable signal is in the logical "0" state.
The configuration permits medium speed operation and assures a hazard-free counting sequence. The 10 decoded outputs are normally in the logical "0" state and go to the logical "1" state only at their respective time slot. Each decoded output remains high for 1 full clock cycle. The carry-out signal completes a full cycle for every 10 clock input cycles and is used as a ripple carry signal to any succeeding stages.