PN SEQUENCE GENERATOR WITH BIDIRECTIONAL SHIFT REGISTER AND EULERIAN-GRAPH FEEDBACK CIRCUIT

摘要

A pseudorandom number sequence generator comprises abidirectional shift register arranged to be loaded with a multi-bit sequence.The shift register is responsive to an ith clock pulse and an ith directioncontrol bit for shifting the multi-bit sequence in one of two directions,delivering an ith output bit and receiving an ith input bit. The multi-bitsequence successively defines one of nodes of an Eulerian graph connectedby branches. A feedback circuit is connected to the shift register forconverting a set of input data to a set of output data. The input datacomprises a multi-bit sequence stored in the shift register in response to an (i+ 1)th clock pulse, the ith output bit and the ith direction control bit andthe output data comprises an (i + 1)th input bit and an (i + 1)th directioncontrol bit. The output data is supplied to the shift register so thatmulti-bit sequences produced by the shift register move around the graphfollowing every branch exactly once, and outputting the (i + 1)th input bitto form a pseudorandom number sequence.