9316

9316 DM9316 Synchronous 4-Bit Counters June 1989 9316 DM9316 Synchronous 4-Bit Counters General Description These synchronous presettable counters feature an internal carry look-ahead for application in high-speed counting designs The 9316 is a 4-bit binary counter The carry output is decoded by means of a NOR gate thus preventing spikes during the normal counting mode of operation Synchronous operation is provided by having all flip-flops clocked simultaneously so that the outputs change coincident with each other when so instructed by the count-enables inputs and internal gating This mode of operating eliminates the output counting spikes which are normally associated with asynchronous (ripple clock) counters A buffered clock input triggers the four flip-flops on the rising (positive-going) edge of the clock input waveform These counters are fully programmable that is the outputs may be preset to either level As presetting is synchronous setting up a low level at the load input disables the counter and causes the outputs to agree with the setup data after the next clock pulse regardless of the levels of the enable input Low-to-high transitions at the load input are perfectly acceptable regardless of the logic levels on the clock or enable inputs The clear function is asynchronous and a low level at the clear input sets of the flip-flop outputs low regardless of the levels of clock load or enable inputs The carry look-ahead circuitry provides for cascading counters for n-b...