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. 19, 1999
Filed:
May. 14, 1997
Joseph Ervin, Stow, MA (US);
Jonathan Crowell, Boston, MA (US);
Digital Equipment Corporation, Maynard, MA (US);
Abstract
An apparatus is provided for reducing read latency for an I/O device residing on a first bus having a first, short read latency timeout period. The apparatus includes a I/O bridge on a second bus having a second, longer read latency timeout compared to that of first bus which modifies read transactions into two separate transactions. A first transaction is a write transaction to the same address requested by the read transaction. This transaction forces a write-back if the address hits in a CPU's write-back cache. Thereafter the read transaction is performed after a predetermined period of time following initiation of the write transaction. This removes the possibility of a device on the first bus having a short read latency timeout period from exceeding it's read latency timeout limit.