Reference Guide

Chapter 4 SCSI Commands
MODE SELECT (6) / (10) Command (15h / 55h)
DLT-S4 Interface Reference Guide 126
Figure 67 SAS — Logical Unit
Control MODE SELECT Page
— Data Format
Table 76 SAS — Logical Unit
Control MODE SELECT Page
— Field Descriptions
Bit
7 6 5 4 3 2 1 0
Byte
0 PS (0) SPF (0) Page Code (18h)
1 Page Length (06h)
2 Reserved
Transport
Layer
Retries
Protocol Identifier (6h)
3 — 7 Reserved
Field Description
PS Parameters Savable. Must be set to 0.
SPF SubPage Format. Always set to 0. Indicates that this page uses the page_0
page format.
Page Code Identifies the type of
MODE SELECT page being transferred. A value of 18h
identifies this as the Logical Unit Control Page.
Page Length Indicates the number of bytes in the page, excluding bytes 0 and 1. The
length is returned on
MODE SENSE and must subsequently be set to the same
value when performing
MODE SELECT.
Protocol Identifier A value of 1h indicates that this mode page applies to a SAS-1.1 compliant
port (see the Information Technology — Serial Attached SCSI – 1. 1 (SAS-1.1)).
Transport Layer Retries When set to 1, transport layer retries are supported by this device as defined
in SAS 1.1. When this bit is set to 0 in a
MODE SELECT command, the device
will disable transport layer retries. The default and recommended value for
this field is 1, transport layer retries enabled.