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. 17, 2000
Filed:
Oct. 19, 1999
Harold Pilo, Underhill, VT (US);
James J Covino, Montpelier, VT (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A comparator and variable delay circuit are provided to maintain the tracking between data and echo clocks in a double data rate (DDR)RAM device. This is accomplished by providing a global data signal (dummy data signal) that tracks with the actual memory array data. This global data signal is compared to the timing of the RAM clock (CLOCK) to determine a delay time between the two by which the pipeline clocks (CLKRISE/CLKFALL) must be delayed. As a result, the pipeline clocks are pushed out as needed so that they always transition after the array data arrives at the output latch. Therefore, as cycle time decreases, both echo clocks and data are pushed out identically and maintain their required tracking.