Test-pattern changeover device for a quasi-random generator with multiplex-signal formation

摘要

A quasi-random generator for high-rate digital test sets, which generates a quasi-random sequence that is a number of times faster, from a plurality of clock-phase-shifted quasi-random sequences, with the aid of a multiplexer, is intended to be provided with a test-pattern changeover device of economical construction. To this end, the quasi-random sequence changeover switch (Fig. 5, top) is implemented by means of suitable connection of integrated, emitter-coupled parallel shift-register modules, and the clock-phase changeover switch (Fig. 5, bottom) which is required for forming the multiplex signal is implemented by means of an integrated, emitter-coupled, triple 4-to-1 multiplexer module. There is in each case only one logic gate or multiplexer passage between two flipflop stages, and every connecting line originating from a module in each case leads to only one further module. The multiplexer bit rate which can be achieved in this way is more than 600 Mbit/s. IMAGE