Reference Guide

Chapter 4 SCSI Commands
MODE SENSE (6) / (10) Command (1Ah / 5Ah)
DLT-S4 Interface Reference Guide 193
Table 109 Parallel SCSI —
SPI Negotiated Settings Mode
Subpage — Field Descriptions
Field Description
PS Parameters Savable. Always set to 0.
SPF SubPage Format. Always set to 1. Indicates that this page uses the
sub_page mode format.
Page Code Identifies the type of
MODE SENSE page being transferred. A value of 19h
identifies this as the Port Control Page.
Subpage Code Identifies the type of
MODE SENSE subpage being transferred. A value of
03h identifies this as the SPI Negotiated Settings Mode Subpage.
Page Length Indicates the number of bytes in the page, excluding the 4 bytes that make
up the header.
Protocol Identifier A value of 1h indicates that this mode page applies to an SPI-5 compliant
port (see the SCSI Parallel Interface – 5 (SPI–5) standard.
Transfer Period Factor Indicates the negotiated Transfer Period Factor for the current I_T nexus
(see the SCSI Parallel Interface – 5 (SPI–5) standard.
REQ/ACK Offset Indicates the negotiated REQ /ACK Offset for the current I_T nexus (see
the SCSI Parallel Interface – 5 (SPI–5) standard).
Transfer Width Exponent Indicates the negotiated REQ /ACK
Offset for the current I_T nexus.
Value Description
00h Specifies 8 bit data bus (i.e.
narrow transfer agreement).
01h Specifies 16 bit data bus (i.e. wide transfer agreement)
Protocol Options Bits Indicates the negotiated Protocol Options for the current I_T nexus (see
the SCSI Parallel Interface – 5 (SPI–5) standard).
Transceiver Mode Indicates the current Transceiver Mode, as defined below:
Code Bus Mode
00b Unknown
01b Single ended
10b Low Voltage Differential
11b High Voltage Differential (not supported)
Sent PCOMP_EN Indicates the PCOMP_EN bit sent for the current I_T nexus.
Received PCOMP_EN Indicates the PCOMP_EN bit received for the current I_T nexus.