User Manual

SCSI Commands Reference Manual, Rev. J 440
www.seagate.com Parameters for direct access devices
5.3.27 Phy Control And Discover subpage (19h/01h)
The Phy Control And Discover subpage contains SAS phy-specific parameters. The mode page policy (see 5.4.14) for this
subpage shall be shared. Parameters in this subpage shall affect only the referenced phy.
Table defines the format of the subpage for SAS.
The PARAMETERS SAVEABLE (PS) bit is defined in 5.3.5.
The SPF bit (see 5.3.5) shall be set to one to access the long format mode pages.
The PAGE CODE field (see 5.3.5) shall be set to 19h.
The SUBPAGE CODE field (see 5.3.5) shall be set to 01h.
The PAGE LENGTH field (see 5.3.5) shall be set to (4 + (the value of the NUMBER OF PHYS field) × (the length in bytes of the SAS phy mode
descriptor)).
PROTOCOL IDENTIFIER field
The PROTOCOL IDENTIFIER field shall be set to 6h indicating this is a SAS specific mode page.
GENERATION CODE field
The GENERATION CODE field is a one-byte counter that shall be incremented by one by the device server every time the values in this mode
page or the Enhanced Phy Control mode page
(see 5.3.29) are changed. A GENERATION CODE field set to 00h indicates the generation code is
unknown. The device server shall wrap this field to 01h as the next increment after reaching its maximum value (i.e., FFh). The GENERATION
CODE field is also contained in the Enhanced Phy Control mode page (see 5.3.29) and the Protocol-Specific Port log page and may be used to
correlate phy settings across mode page and log page accesses.
NUMBER OF PHYS field
The NUMBER OF PHYS field contains the number of phys in the SAS target device and indicates the number of SAS phy mode descriptors that
follow. This field shall not be changeable with MODE SELECT.
Table 412 SAS - Phy Control And Discover subpage
Bit
Byte
7 6 5 4 3 2 1 0
0
PS SPF (1b) PAGE CODE (19h)
1
SUBPAGE CODE (01h)
2
(MSB)
PAGE LENGTH (N - 3)
3
(LSB)
4
Reserved
5
Reserved PROTOCOL IDENTIFIER (6h)
6
GENERATION CODE
7
NUMBER OF PHYS
SAS phy mode descriptor list
8
FIRST SAS PHY MODE DESCRIPTOR (see table 413)
. . .
. . .
. . .
. . .
LAST SAS PHY MODE DESCRIPTOR (see table 413)
n