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:
Jun. 27, 2006
Filed:
Aug. 21, 2000
John M. Callahan, San Ramon, CA (US);
John M. Callahan, San Ramon, CA (US);
Nanoamp Solutions, Inc., San Jose, CA (US);
Abstract
To determine the occurrence of an address for a defective memory, cell in a ROM, an error-correction control system includes a comparator that compares a set of incoming memory address signals with static signals provided by a laser-fuse array. The static signals represent addresses of defective memory cells in the ROM. An ADDHIT signal indicates that the ROM has received an address of a defective memory cell. The ADDHIT signal is then timed to provide a REV signal that changes the polarity of the memory bit signal out of a buffer circuit. This corrects an erroneous memory cell by reversing the sense of the memory bit received from a defective memory cell and delivered to an output terminal of the ROM. The REV signal is steered to an output buffer corresponding to the proper ROM chip output pad using a fuse-controlled selection circuit. A plurality of defective memory cells are corrected by using a number of comparators to compare input address signals to a number of fuse-controlled static addresses, each representing a defective memory cell.