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:
Oct. 26, 1999
Filed:
May. 22, 1997
Abeye Teshome, Austin, TX (US);
Dell Computer Corporation, Round Rock, TX (US);
Abstract
In a computer including two buses, a main memory, a write back cache, and a peripheral device, a method and apparatus for providing an inter-bus buffer to support successive main memory accesses from the peripheral device is disclosed. The buffer is included in a bridge device for interfacing the two computer buses and controlling when the peripheral device may access the main memory. When the peripheral device attempts to read data from the main memory that is duplicated in the cache and that has become stale, the bridge device initiates a write back operation to update specific data portions of the main memory corresponding to the read request. The bridge device uses look-ahead techniques such as bursting or pipelining to streamline the data coming from the cache to the main memory and to the peripheral device. When the peripheral device requests a misaligned memory read operation, upon termination of the read access due to preemption of the peripheral device, the cache line containing the remainder of the requested data is written back to the main memory, and stored in the buffler. The bridge device can then use the data stored in the buffer to respond to subsequent memory access requests from the peripheral device.