The CD4017B is a 5-stage Johnson counter with 10 decoded outputs. The counter advances one count at the positive clock signal transition if the CLOCK INHIBIT signal is low. Counter advancement is inhibited when CLOCK INHIBIT is high. A high RESET signal clears the counter to its zero count. Each decoded output remains high for one full clock cycle. The CARRY-OUT signal completes one cycle every 10 clock input cycles.
Use of the Johnson counter configuration permits high-speed operation, 2-input decode-gating and spike-free decoded outputs. The decoded outputs are normally low and go high only at their respective decoded time slot.