The FCT191T is a reversible modulo-16 binary counter, featuring synchronous counting and asynchronous presetting. The preset allows the FCT191T to be used in programmable dividers. The count enable input, terminal count output, and ripple clock output make possible a variety of methods of implementing multiusage counters. In the counting modes, state changes are initiated by the rising edge of the clock. The outputs are designed with a power-off disable feature to allow for live insertion of boards.