The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 18, 1992
Filed:
Jan. 22, 1991
Makoto Murase, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
A linear feedback shift register comprises a shift register formed of first to (n)th flipflops cascaded in such a manner that an output of a (i)th flipflop is connected to an input of a (i+1)th flipflop, where 2.ltoreq.n and 1.ltoreq.i.ltoreq.(n-1). First to (n)th output terminals are connected to outputs of the first to (n)th flipflops, respectively, and a clock terminal connected to a clock input of each of the flipflops. First to (n-1)th multiplexors of a '1-out-of-2' type are connected at their first input to a common preset value input terminal. Second inputs of the first to (n-1)th multiplexors are connected to the outputs of the first to (n-1)th flipflops, respectively. Each of the first to (n-1)th multiplexors has a control input connected to an individual control terminal. First to (n-1)th exclusive-OR gates are cascaded in such a manner that a first input of a (n-1)th exclusive-OR gate is connected to the output of the (n)th flipflop, a first input of an (i)th exclusive-OR gate is connected to an output of an (i+1)th exclusive-OR gate, and an output of the first exclusive-OR gate is connected to an input of the first flipflop. A second input of the (i)th exclusive-OR gate is connected to an output of the (i)th multiplexor. With this arrangement, a generator polynomial generated by the linear feedback shift register can be modified by controlling the multiplexors through the individual control terminals.