User Manual

SCSI Commands Reference Manual, Rev. J 156

www.seagate.com Direct Access Block commands (SPC-5 and SBC-4)

3.22.2 READ CAPACITY (10) parameter data

The READ CAPACITY (10) parameter data is defined in table 120. Any time the READ CAPACITY (10) parameter data changes, the device server

should establish a unit attention condition as described in SBC-4.

RETURNED LOGICAL BLOCK ADDRESS field

If the number of logical blocks exceeds the maximum value that is able to be specified in the RETURNED LOGICAL BLOCK ADDRESS field, the

device server shall set the RETURNED LOGICAL BLOCK ADDRESS field to FFFFFFFFh. The application client should then issue a READ CAPACITY

(16) command

(see 3.24) to retrieve the READ CAPACITY (16) parameter data.

0 If the PMI bit is set to zero, the device server shall set the RETURNED LOGICAL BLOCK ADDRESS field to the lower of:

a) the LBA of the last logical block on the direct-access block device; or

b) FFFFFFFFh.

1 If the PMI bit is set to one, the device server shall set the RETURNED LOGICAL BLOCK ADDRESS field to the lower of:

a) the last LBA after that specified in the LOGICAL BLOCK ADDRESS field of the CDB before a substantial vendor-specific delay in data

transfer may be encountered; or

b) the LBA of the last logical block on the direct-access block device.

The RETURNED LOGICAL BLOCK ADDRESS shall be greater than or equal to that specified by the LOGICAL BLOCK ADDRESS field in the CDB.

BLOCK LENGTH IN BYTES field

The BLOCK LENGTH IN BYTES field contains the number of bytes of user data in the logical block indicated by the RETURNED LOGICAL BLOCK

ADDRESS field. This value does not include protection information or additional information (e.g., ECC bytes) recorded on the medium.

Table 120 READ CAPACITY (10) parameter data

Bit

Byte

7 6 5 4 3 2 1 0

(MSB)

RETURNED LOGICAL BLOCK ADDRESS

. . .

(LSB)

(MSB)

BLOCK LENGTH IN BYTES

. . .

(LSB)