IC DM74LS393
Each of these monolithic
circuits contains eight master-slave flip-flops and additional gating to implement two indi-vidual four-bit counters in a single package.
The DM74LS393 comprises two independent four-bit binary counters each having a clear and a clock input. N-bit binary counters can be implemented with each package providing the capability of divide-by-256.
The DM74LS393 has paral-lel outputs from each counter stage so that any submultiple of the input count frequency is available for system-timing signals