74LS168.pdf 54LS168 Synchronous Bi-Directional BCD Decade Counter June 1989 54LS168 Synchronous Bi-Directional BCD Decade Counter General Description The 54LS168 is a fully synchronous 4-state up down coun- ter featuring a preset capability for programmable operation carry lookahead for easy cascading and a U D input to con- trol the direction of counting It counts in the BCD (8421) sequence and all state changes whether in counting or par- allel loading are initiated by the LOW-to-HIGH transition of the clock ……