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:
Aug. 19, 2003
Filed:
Aug. 29, 2002
Billy Wayne Garrett, Jr., Mountain View, CA (US);
John B. Dillon, late of Palo Alto, CA (US);
Michael Tak-Kei Ching, Sunnyvale, CA (US);
William F. Stonecypher, San Jose, CA (US);
Andy Peng-Pui Chan, San Jose, CA (US);
Matthew M. Griffin, Mountain View, CA (US);
Rambus Inc., Los Altos, CA (US);
Abstract
A memory system and method of adjusting an output driver characteristic of a memory device that is included in the memory system. The method includes providing a command to the memory device that specifies a calibration mode and, during the calibration mode, driving a voltage level onto the first signal line using a first output driver. A first voltage level is derived from an amount of voltage swing generated by the first output driver driving the voltage level onto the first signal line. The method also includes: actively coupling a first comparator to the first signal line; when the first comparator is coupled to the first signal line, comparing the first voltage level with a reference voltage using the first comparator; and adjusting the amount of voltage swing to arrive at a calibrated voltage swing level. In addition, the method includes actively isolation the first comparator from the first signal line upon exiting the calibration mode. The memory device is operable in a normal read operation upon exiting the calibration mode. During the normal read operation, the first output driver is operable to output data onto the first signal line in accordance with the calibrated voltage swing level.