Method for directing I/O transactions between an I/O device and a memory
US5991797A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 23, 1997 |
| Grant date | Nov 23, 1999 |
| Priority date | — |
| Expiry date | Dec 23, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F9/54
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A first host system directs an I/O device to transfer data directly between a requesting application program's buffers on a second host system and an I/O unit coupled to the I/O device without the need to pass through the first host system. Since the first host system retains control of the I/O request, it maintains security and protection features at the same time as realizing increases in performance gained from not having to participate in the actual data transfer. This direct movement capability supports peer-to-peer operation where a number of different I/O units, each with its own physical memory addressing domain, require access to the same I/O device. The direct movement capability is also useful in clustered systems. Clustered host systems are allowed direct access to an I/O device for data transfer without intervention by the host system owning the I/O device.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.