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:
Mar. 19, 2002
Filed:
Mar. 02, 2000
James Park, San Jose, CA (US);
Wei-Jen Huang, Burlingame, CA (US);
Tony Ngai, Campbell, CA (US);
Bruce B. Pedersen, San Jose, CA (US);
Altera Corporation, San Jose, CA (US);
Abstract
A programmable logic device is adapted to predict carry values in long-chain-carry logic configurations. In the most preferred embodiment, which functions in any long-carry-chain logic configuration, each logic region calculates a result for both values of the carry-in signal to that region, and when a carry signal for the group to which the region belongs reaches the region, the correct result in each region, and thence the correct carry-out for that group, are calculated and propagated. The carry-out terminal of one group is arranged to be adjacent to the carry-in terminal of the next group, to enhance carry propagation speed. In another embodiment, each region looks back two regions to predict the carry-in. In two additional embodiments, logic is provided to mathematically calculate the carry values.