User Manual

SCSI Commands Reference Manual, Rev. J 49

www.seagate.com General Concepts

2.4.1.1.2 Information sense data descriptor

The information sense data descriptor (see table 15) provides information that is device-type or command specific and is

defined in a command standard.

DESCRIPTOR TYPE and ADDITIONAL LENGTH fields

The DESCRIPTOR TYPE and ADDITIONAL LENGTH fields are described in 2.4.1.1.1. For the information sense data descriptor, the DESCRIPTOR

TYPE field shall be set to 00h and the ADDITIONAL LENGTH field shall be set to 0Ah.

VALID bit

The VALID bit shall be set to one.

NOTE In the fixed format sense data, the VALID bit indicates whether the contents of the INFORMATION field

is valid as defined by a command standard. Since the contents of the INFORMATION field are valid

whenever an information sense data descriptor is included in the sense data, the only legal value for

the VALID bit is set to one.

INFORMATION field

The contents of the INFORMATION field are device-type or command specific and are defined in a command standard. When a four byte quan-

tity is stored in the INFORMATION field, the first four bytes shall be zero.

2.4.1.1.3 Command-specific information sense data descriptor

The command-specific information sense data descriptor (see table 16) provides information that depends on the command on

which the exception condition occurred.

Table 15 Information sense data descriptor format

Bit

Byte

7 6 5 4 3 2 1 0

DESCRIPTOR TYPE (00h)

ADDITIONAL LENGTH (0Ah)

VALID (1b) Reserved

Reserved

(MSB)

INFORMATION

. . .

(LSB)

Table 16 Command-specific information sense data descriptor format

Bit