hesela.devSAS physical PHY
The SAS physical-layer endpoint containing the transceiver that connects to another physical PHY over a link.
The physical link has a transmit differential pair and a receive differential pair, permitting simultaneous traffic in both directions. A PHY is an endpoint of that link, not the entire port or the external plug. [1]
A SAS port contains one or more PHYs, while one connector may carry links belonging to different ports. [2] Linux exposes PHY and port management separately, so a PHY identifier must be kept with its device and topology context when interpreting link events. [3]
Relations
- related
- sas, sas-wide-port, sas-expander, sas-phy-event-counters
Citations
- IBM Power6 documentation: SAS architecture
- Oracle HBA guide: SAS phys, ports, addresses and connectors (2010), appendix G
- Linux kernel documentation: SAS Layer
- Seagate SAS Interface Manual, Rev. C (2009), sections 2.1.2, 2.1.4 and 5.11.1-2
Sources & caveats
- Scope is the physical PHY; the SAS architecture also uses logical and virtual PHY concepts. Seagate Rev. C sections 1.3.3 and 2.1.2 distinguish them. [4]