Serial ATA technology, 4th edition

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Appendix: SATA terminology
Table 1: SATA terminology
Term Definition
Entry drives SATA drives that provide a basic level of reliability and performance for
environments that are not mission critical.
Expander A SAS device that functions as a switch to attach one or more initiators to one or
more targets
Frame Information
Structure
A FIS is a packet that may contain ATA register contents, data, control
information, or other information.
Host The initiator of communication with a SATA device
Logical drive A partitioned space on physical devices
Midline devices SATA drives that provide larger capacity and greater reliability than Entry-
drives, making them better suited for multi-drive configurations.
PHY The mechanism that contains a transceiver, which electrically connect to a
physical link
Physical link Two differential signal pairs, one pair in each direction, that connect two
physical PHYs
SATA Tunneled Protocol
(STP)
A protocol used to communicate with SATA devices in a SAS topology.
Target A disk drive or solid-state drive