Command Specifications

e.Block descriptor length

This field indicates the "Block descriptor" length (byte length) which follows after the header. The "Page descriptor" length is not included in this value. The HDD always reports X '08' in this field if "0" is specified in the DBD bit of this command's CDB, and thus indicates that one "Block descriptor" set follows after the header. When "1" is specified in the DBD bit of the CDB, the value of this field is X '00'.

(2)Block descriptor

The 8-byte "Block descriptor" indicates the logical attributes of the data format on the disk media.

a.Data block count

This field indicates the total number of logical data blocks (the block length is shown in the "Data block length" field) existing in the "User Space" on the disk media. This value does not include the number of spare sectors reserved for alternate block processing.

Furthermore, when this command specifies to transfer the "Default" value and "Variable" value, the value shown in this field is X '000000' (which means the maximum number of logical data blocks that it is possible to rank in the "User Space").

b.Data block length

This field indicates the length (byte length) of 1 logical data block on the disk media.

(3) Page descriptor

The "Page descriptor" is configured from a parameter field which follows a 2-byte page header, and is divided into units called "Page" for each parameter's functional attributes. See the description of the MODE SELECT command (Section 4.1.4) concerning the configuration of each page descriptor and their contents.

a.PS bit

When this bit is "1," the parameter value defined in that "Page descriptor" can be saved on the disk media, and when it is "0", it indicates that this is a parameter which cannot be saved to the disk. It is possible to save all the "Page descriptors" supported by the HDD. However, "1" is always indicated in this bit for all "Page descriptors" transferred by this command.

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Fujitsu MBC2073RC, MBC2036RC, MBA3300RC, MBA3147RC, MBA3073RC specifications Block descriptor, Descriptor