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. 25, 2011
Filed:
Jun. 01, 2009
John Birkner, Woodside, CA (US);
Andrew Ka Lab Chan, Palo Alto, CA (US);
John Birkner, Woodside, CA (US);
Andrew Ka Lab Chan, Palo Alto, CA (US);
Siliconblue Technologies Corporation, Santa Clara, CA (US);
Abstract
An in-FPGA carry chain is provided that does not exhibit significant leakage current. In particular, parts of the carry chain can be switched on/off when desired. In this manner, carry chain parts can have their leakage currents substantially disabled when they are not in use, thus saving power. Additionally, there is provided a carry chain whose logic is separate from the other parts (e.g., LUTs) of the logic blocks that perform the remaining arithmetic functions, and whose inputs are the input data to be added, rather than data that is output in delayed fashion from the other parts (e.g., LUTs) of the logic blocks. Such a configuration reduces latency by allowing the carry chain to operate directly on the received input data without need to wait on results from the other parts (e.g., LUTs) of the logic blocks.