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:
Jul. 26, 2005
Filed:
Feb. 07, 2002
Terry C. Coughlin, Jr., Endicott, NY (US);
Geoffrey Wang, Endicott, NY (US);
Terry C. Coughlin, Jr., Endicott, NY (US);
Geoffrey Wang, Endicott, NY (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A method of, and a circuit for, impedance control. The method comprises the steps of providing an input/output cell having a controllable input/output impedance, providing a reference cell including a node having a variable voltage, and comparing the voltage of the node to a reference voltage. The voltage of the node is adjusted during a defined period and according to a defined procedure, and during that defined period, a digital signal is generated. That digital signal is transmitted to the input/output cell to adjust the input/output impedance. Preferably, the circuit is embodied as a digital controller designed as a synthesized core or macro. The advantage of this implementation is that it never has to be redesigned in future technologies. The digital controller may be carried over to future technologies in the form of VHDL code, which is pure logic and independent of technology.