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Spoiler Family That Removes Linear Dependencies From an LFSR Response

IP.com Disclosure Number: IPCOM000064294D
Original Publication Date: 1985-Jun-01
Included in the Prior Art Database: 2005-Feb-18

Publishing Venue

IBM

Related People

Authors:
Savir, J [+details]

Abstract

This article relates to the use of a linear feedback shift register (LFSR) as a random pattern generator for self-test using a maximal length LFSR, which has the property of producing all possible r-sequences (r is the length of the LFSR), except for the all-zero response (00...0). An application for generating random sequences is shown in Fig. 1. The LFSR of Fig. 1 produces random bits that are scanned into the SRL chain. After enough clocks (enough to fill the SRL chain with random data) the SRL outputs are random for all practical purposes, and can be used as random stimuli to the logic it feeds. However, if the SRL chain length is longer than the LFSR length (which is usually the case), not all m (m>r) sequences are present at the SRL outputs [*].