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. 11, 1998
Filed:
Jul. 19, 1996
Dwight D Riley, Houston, TX (US);
David J Maguire, Spring, TX (US);
Compaq Computer Corporation, Houston, TX (US);
Abstract
The present invention relates to a system and method for shadowing data of a first register and a second register of a computer system that share a common address. When a bus agent runs a write operation to the register address, retry logic of a first bridge circuit retries the write operation and masks access by the bus agent to the bus. Retry bus master logic reruns the write operation, in response to which the second bridge circuit subtractively decodes the rerun write operation and transfers the data to the second register. The bus agent is then allowed to retry the initial write operation, in response to which the first bridge circuit positively decodes the retried write operation and transfers the data to the first register. Thus, coherency is preserved between the first and second registers.