The HC40103 consists of an 8 stage synchronous down counter with a single output which is active when the internal count is zero. The HC40103 contains a single 8-bit binary counter. This device has control inputs for enabling or disabling the clock, for clearing the counter to its maximum count, and for presetting the counter either synchronously or asynchronously. All control inputs and the CARRY-OUT / ZERO DETECT output are active low logic. In normal operation the counter is decremented by one count on each positive transition of the CLOCK. Counting is