The NJ88C24 is a synthesiser circuit fabricated on the Plessey small geometry CMOS process; it is practically identical to the NJ88C22; the only difference is the resettable counter.
When re-programming, the counters are changed only at the zero state. There is no reset to zero , which means that the
synthesiser loop lock-up time will be variable. When only small changes in frequency are required, the non-resettable
synthesiser should achieve the shortest loop lock-up times.