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:
Oct. 05, 1993
Filed:
Jan. 13, 1992
Applicant:
Inventors:
Subrahmanyam Dravida, Highland Park, NJ (US);
Daniel S Greenberg, Troy Hills, NJ (US);
David J Hodgdon, Troy Hills, NJ (US);
Assignee:
AT&T Bell Laboratories, Murray Hill, NJ (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G06F / ;
U.S. Cl.
CPC ...
370 941 ; 370 99 ; 371 371 ; 371 377 ; 371 381 ; 371 391 ; 371 44 ; 341 94 ;
Abstract
Disclosed is a method and circuit for modifying the check code of a data packet based on a first seed to accommodate the addition or substraction of a header. A number of bits, which include a second seed, an exclusive OR function of the first seed and a portion of a header, and a string of zeros dependent upon the length of an incoming data packet, is sent through a CRC generator. The resulting CRC calculation and the incoming packet check code are exclusive ORed to produce a modified check code taking into account the addition or substraction of the header.