These synchronous, presettable counters feature an internal carry look-ahead for application in high-speed counting designs. The 'ALS160B, 'ALS162B, 'AS160, and 'AS162 are decade counters, and the 'ALS161B, 'ALS163B, 'AS161, and 'AS163 are 4-bit binary counters. 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-enable inputs and internal gating. This mode of operation eliminates the output counting spikes that 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.