The MC3101 implements a counter that counts down from a given input. The counter counts down each time clock input toggles from low to high, it starts from a predefined value to 0. Output is high when counter reaches 0. If in 'infinite' mode, it will automatically reset the next time clock is toggled. Otherwise, it only resets when the 'reset' input toggles from low to high.
- Third line: #:ONCE or ##:INF -- where ## is the counter reset value, and ONCE or INF specifies if the counter should repeat or not.