The MC54/ 74F568 and MC54/74F569 are fully synchronous, reversible counters with 3-state outputs. The F568 is a BCD decade counter; the F569 is a binary counter. They feature preset capability for programmable operation, carry lookahead for easy cascading, and a U/D input to control the direction of counting. For maximum flexibility there are both synchronous and master asynchronous reset inputs as well as both Clocked Carry (CC) and Terminal Count (TC) outputs. All state changes except Master Reset are initiated by the rising edge of the clock. A HIGH signal on the Output Enable (OE) input forces the output buffers into the high impedance state but does not prevent counting, resetting or parallel loading.