Technical information

HGST Ultrastar C15K600 Hard Disk Drive Specification
63
17.4
PHY Layer
The PHY layer defines 8b10b encoding and OOB signals. The PHY layer is the interface between the link layer and
the physical layer. This section describes PHY layer behaviors of the drive. For a complete description of SAS PHY
Layer, please see the ANSI specification, SPL-3.
17.4.1
Link Reset Sequence
The Link Reset sequences for SAS are defined in the SPL-3 ANSI specification with a general overview shown
below. As shown in the diagram, a PHY Reset sequence, consists of an OOB sequence, followed by speed
negotiation. Link Reset sequences will always include a PHY Reset sequence, followed by an Identification
sequence. Inclusion of a Hard Reset sequence is optional. If Hard Reset is performed, it will be preceded by a PHY
Reset sequence, and followed by PHY Reset and an Identification sequence.
Link Reset Sequence with hard Reset
Time
Phy Reset sequence
Identification sequence
Phy Reset sequence Hard Reset Sequence
Phy Reset sequence Identification sequence
Time
SAS
SAS w/Hard Reset
Link Reset sequence
OOB sequence Speed Negotiation
sequence
Figure 6 Link Reset Sequence