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:
Dec. 05, 2000
Filed:
Dec. 30, 1997
Eli Shagam, Brookline, MA (US);
EMC Corporation, Hopkinton, MA (US);
Abstract
A method for counting the number of bits which are set to binary '1' in a word of length 2.sup.n includes generating a first mask of length 2.sup.n having alternating sequences of '1''s and '0''s, each sequence having a length 'x' (the length 'x' initially having a value of 1), and generating a second mask of length 2.sup.n by forming the complement of the first mask. Logical AND operations using the word and each of the first and second masks are performed to generate first and second intermediate words, respectively. That one of the first and second intermediate words having been ANDed with one of the first and second masks having a '0' in its least significant bit position, is shifted 'x' number of bit positions to generate a shifted intermediate word. The shifted intermediate word and the other of the first and second intermediate words are arithmetically added to generate a bit-counted word of 2.sup.n length representing the number of bits in the word set to binary '1' from the bit-counted word. The value of 'x' is doubled and the method is repeated 2.sup.n iterations.