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:
Sep. 02, 1997
Filed:
Apr. 21, 1995
James P Kardach, Saratoga, CA (US);
Sung-Soo Cho, Sunnyvale, CA (US);
Jim S Cheng, Cupertino, CA (US);
Debra T Cohen, Sunnyvale, CA (US);
John W Horigan, Mountain View, CA (US);
Nader Raygani, San Jose, CA (US);
Seyed Yahay Sotoudeh, Santa Clara, CA (US);
David I Poisner, Folsom, CA (US);
Neil W Songer, Santa Clara, CA (US);
Intel Corporation, Santa Clara, CA (US);
Abstract
A computer system that implements a direct memory access (DMA) request passing protocol. The computer system may comprise a Peripheral Component Interconnect (PCI) bus that includes an electrical interface as specified by a PCI Local Bus standard. The PCI bus is coupled to at least one DMA agent and a DMA controller. The DMA agent issues DMA requests to the DMA controller using the electrical interface of the PCI bus. According to one embodiment, a system I/O controller receives the DMA requests and passes them on to the DMA controller, which arbitrates the DMA requests and passes back a grant to the system I/O controller. The system I/O controller uses the electrical interface of the PCI bus to pass the grant to the DMA agent. The same DMA request passing protocol may be implemented in any bus having an electrical interface that specifies a unique request signal line for each bus agent of the bus.