74LS190 BCD/Decade Up/Down Counter 4-Bit Binary - (AD21968)

Description:

The SN54/74LS190 is a synchronous up/down BCD (8421) decade counter, and the SN54/74LS191 is a synchronous up/down modulo-16 binary counter. The state changes of the counters are synchronous with the low-to-high transition of the clock pulse input. An asynchronous parallel load (PL) input overrides counting and loads the data present at the Pn inputs into the flip-flops, allowing the circuits to be used as programmable counters. A count enable (CE) input serves as a carry/borrow input in multistage counters. An up/down (U/D) count control input determines whether a circuit counts up or down. A terminal count (TC) output and a ripple clock (RC) output provide overflow/underflow indication and enable various methods for generating carry/borrow signals in multistage counter applications.

Datasheet