Hierarchical device spin-up control for serial attached devices
US7474926B1 · kind B1 · utility
37Cited by
4References
22Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Mar 28, 2006 |
| Grant date | Jan 6, 2009 |
| Priority date | — |
| Expiry date | Jan 5, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B19/209
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method and apparatus are provided for controlling the powering-up or spin-up of devices such as hard drives using expanders in a SAS topology. The method and apparatus provides a mechanism to coordinate spin-up control among a topology of expanders. The present invention enables an expander to both process the reception of the NOTIFY command to spin up attached devices and to propagate such command to further expanders. Hierarchical spin-up control provides an advantageous, in-band mechanism that controls the expanders within the topology to limit the total number of devices powering-up at any given time.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.