HD74LS193

HD74LS193 Synchronous Up / Down Decade Counter (dual clock lines) REJ03D0455–0200 Rev.2.00 Feb.18.2005 Synchronous operation is provided by having all flip-flops clocked simultaneously so that the output change coincidently with each other when so instructed by the steering logic. This mode of operation eliminates the output counting spikes, which are normally associated with asynchronous (ripple clock) counters. The outputs of the four master-slave flip-flops are triggered by a low-to-high-level transition of either count (clock) input. The direction of counting is determined by which count input is pulsed while the other count input is high. This counter is fully programmable; that is, each output may be preset to either level by entering the desired data at the data inputs while the load inputs is low. The output will change to agree with the data inputs independently of the count pulses. This feature allows the counters to be used as modulo-N dividers by simply modifying the cou...