Description
The SN54HC191-DIE is a 4-bit synchronous, reversible, up/down binary counter. Synchronous counting operation is provided by having all flip-flops clocked simultaneously so that the outputs change coincident with each other when instructed by the steering logic. This mode of operation eliminates the output counting spikes normally associated with asynchronous (ripple-clock) counters.

Features
• Wide Operating Voltage Range
• Low Power Consumption
• Low Input Current
• Single Down/Up Count-Control Line
• Look-Ahead Circuitry Enhances Speed of Cascaded Counters
• Fully Synchronous in Count Modes
• Asynchronously Presettable With Load Control