1 scsi control byte, 2 abbreviations, 3 byte ordering conventions – Hitachi ULTRASTAR 15K450 HUS154530VLF400 User Manual

Page 133: Table 95.scsi control byte

Advertising
background image

Hitachi Ultrastar 15K450 (FC-AL) Hard Disk Drive Specification

117

19.1 SCSI Control Byte

The Control Byte is the last byte of every CDB. The format of this byte is shown below.

Table 100: SCSI Control Byte

VU

VU stands for Vendor Unique.

FLAG**

If Link is zero, Flag must also be zero. If Link is one, Flag may also be one. Typically this bit is used to cause an
interrupt in the Initiator between linked commands.

LINK**

This bit is set to one to indicate that the Initiator desires an automatic link to the next command upon successful com-
pletion of the current command.

Note: * - The drive ignores the link bit and flag bit in the CDB.

19.2 Abbreviations

These abbreviations are used throughout the following sections:

LUN

Logical Unit Number. An encoded three bit identifier for the logical unit.

VU

Vendor Unique bits

LBA

Logical Block Address

RSVD

Reserved

MSB

Most Significant Byte

LSB

Least Significant Byte

19.3 Byte ordering conventions

In this specification, where it is not explicitly stated, all multi-byte values are stored with the most significant byte first. For
example, in a 4 byte field, byte 0 will contain the MSB and byte 3 the LSB.

BIT

7

6 5 4 3 2 1 0

VU = 0

Reserved = 0

FLAG

LINK

Advertising
This manual is related to the following products: