SN74LS191
SN74LS191 is PRESETTABLE BCD/DECADE UP/DOWN COUNTERS manufactured by Motorola Semiconductor.
- Part of the SN74LS190D comparator family.
- Part of the SN74LS190D comparator family.
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 circuits as programmable counters. A Count Enable (CE) input serves as the carry / borrow input in multi-stage counters. An Up / Down Count Control (U/D) input determines whether a circuit counts up or...
