DM74161

DM54161 DM74161 DM74163 Synchronous 4-Bit Counters October 1992 DM54161 DM74161 DM74163 Synchronous 4-Bit Counters General Description These synchronous presettable counters feature an internal carry look-ahead for application in high-speed counting designs The 161 and 163 are 4-bit binary counters 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 flipflops clocked simultaneously so that the outputs change coincident with each other when so instructed by the countenable inputs and internal gating This mode of operation 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...