Seagate ST91000640NS ユーザーズマニュアル

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Constellation.2 Serial ATA Product Manual, Rev. B
3
Constellation.2 Serial ATA Self-Encrypting Drive models have the following additional features:
• Automatic data encryption/decryption
• Controlled access
• Random number generator
• Drive locking
• 16 independent data bands
• Cryptographic erase of user data for a drive that will be repurposed or scrapped
• Authenticated firmware download
Note.
There is no significant performance difference between Self-Encrypting Drive and standard (non-
Self-Encrypting Drive) models.
2.1
About the Serial ATA interface
The Serial ATA interface provides several advantages over the traditional (parallel) ATA interface. The primary 
advantages include:
• Easy installation and configuration with true plug-and-play connectivity. It is not necessary to set any jump-
ers or other configuration options.
• Thinner and more flexible cabling for improved enclosure airflow and ease of installation.
• Scalability to higher performance levels.
In addition, Serial ATA makes the transition from parallel ATA easy by providing legacy software support. Serial 
ATA was designed to allow you to install a Serial ATA host adapter and Serial ATA disc drive in your current 
system and expect all of your existing applications to work as normal.
The Serial ATA interface connects each disc drive in a point-to-point configuration with the Serial ATA host 
adapter. There is no master/slave relationship with Serial ATA devices like there is with parallel ATA. If two 
drives are attached on one Serial ATA host adapter, the host operating system views the two devices as if they 
were both “masters” on two separate ports. This essentially means both drives behave as if they are Device 0 
(master) devices.
Note.
The host adapter may, optionally, emulate a master/slave environment to host software where two 
devices on separate Serial ATA ports are represented to host software as a Device 0 (master) and 
Device 1 (slave) accessed at the same set of host bus addresses. A host adapter that emulates a 
master/slave environment manages two sets of shadow registers. This is not a typical Serial ATA 
environment.
The Serial ATA host adapter and drive share the function of emulating parallel ATA device behavior to provide 
backward compatibility with existing host systems and software. The Command and Control Block registers, 
PIO and DMA data transfers, resets, and interrupts are all emulated.
The Serial ATA host adapter contains a set of registers that shadow the contents of the traditional device regis-
ters, referred to as the Shadow Register Block. All Serial ATA devices behave like Device 0 devices. For addi-
tional information about how Serial ATA emulates parallel ATA, refer to the “Serial ATA: High Speed Serialized 
AT Attachment” specification. The specification can be downloaded from www.serialata.org.