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:
Jan. 06, 2009
Filed:
Mar. 12, 2007
Bret R. Dale, Jericho, VT (US);
Darin J. Daudelin, Williston, VT (US);
Todd M. Fisher, Essex Junction, VT (US);
Douglas W. Stout, Milton, VT (US);
Bret R. Dale, Jericho, VT (US);
Darin J. Daudelin, Williston, VT (US);
Todd M. Fisher, Essex Junction, VT (US);
Douglas W. Stout, Milton, VT (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
The inventions herein are directed to an inventive bus keeper and logic circuit for use with an I/O circuit, for example, for use on the receiver side of the I/O buffer circuit. The inventive circuit connects one data line of an IC function to one line of a tri-state bus (one bit of data per bus line or wire). The bus keeper and logic control circuit is maintained in isolation from I/O functional driver and is responsive to a tri-state signal (TS), normally provided by the IC or SOC, or the I/O circuit during normal I/O receiver side operation. The inventive bus keeper and logic circuit selectively enables any of a tri-state state, a pull-up state, pull-down state and bus keep mode state at the driver output pad in the presence of the tri-state enable signal, and is disabled when the I/O bus drive buffer circuit is in drive mode.