Abstract: Method and apparatus for generating a pseudo-random binary pattern having a variable characteristic polynomial. The pseudo-random binary pattern is formed as a plurality of serial bit streams, with corresponding bits in each stream forming together one of successive w-bit words in the binary pattern. A plurality of linear feedback shift register (LFSR) sequence generators are each arranged to generate bits for respective ones of the serial bit streams. Each LFSR generator includes a plurality of stages, the stages having an input stage, at least one intermediate stage, and an output stage, the stages being coupled for sequential propagation of signals through the stages. At least one of the stages in each LFSR generator is responsive to a respective control signal for that stage to determine whether signal propagation through that stage is influenced by a feedback signal for that LFSR generator.