54LS191 PDF File ( Datasheet )

PRESETTABLE BCD, DECADE UP, DOWN COUNTERS PRESETTABLE 4-BIT BINARY UP, DOWN COUNTERS The SN54 , 74LS190 is a synchronous UP, DOWN BCD Decade (8421) Counter and the SN54, 74LS191 is a synchronous UP , DOWN Modulo-16 Binary Counter. 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 on the Pn inputs into the flip-flops, which makes it possible to use the c