Hitachi HDT725025VLA380 Specifications - Page 118

SCT Command Transport Feature Set

Page 118 highlights

10.17.5 Read Continuous bit If the Read Continuous bit is set to one for the command, the device shall transfer the requested amount of data to the host within the Command Completion Time Limit even if an error occurs. The data sent to the host by the device in an error condition is vendor specific. 10.17.6 Write Continuous bit If the Write Continuous bit is set to one for the command, and an error is encountered, the device shall complete the request without posting an error. If an error cannot be resolved within the Command Completion Time Limit, the erroneous section on the media may be unchanged or may contain undefined data. A future read of this area may not report an error, even though the data is erroneous. 10.17.7 Handle Streaming Error bit The Handle Streaming Error bit specifies to the device that this command starts at the LBA of a recently reported error section, so the device may attempt to continue its corresponding error recovery sequence where it left off earlier. This mechanism allows the host to schedule error recovery and defect management for content critical data. 10.17.8 Streaming Logs The Streaming Data Transfer feature set requires two error logs and one performance log. These logs are accessed via the Read Log Ext command; the information included in the error logs is volatile and is not maintained across power cycles, hard resets, or sleep. These error logs are 512 bytes in length and retain the last 31 errors that occurred during any Streaming Data transfer. 10.18 SCT Command Transport Feature Set SMART Command Transport (SCT) is the method for the drive to receive commands using log page E0h and transporting data using log page E1h. These log pages are used as follows: Write log page Read log page Log page E0h Issue Command Return Status Log page E1h Send Data to the drive Received Data from the drive There are two ways to access the log pages: using SMART READ/WRITE LOG and READ/WRITE LOG EXT. Both sets of commands access the same log pages and provide the same capabilities. The log directory for log pages E0h and E1h should report a length of one. The length of log page E1h does not indicate the length of an SCT data transfer. If SMART is supported, but not enabled, the drive supports SMART READ/WRITE LOG for Log page E0h and E1h. If security is enabled and password has not been issued to unlock the device, all SCT commands will fail. Deskstar T7K500 Hard Disk Drive Specification 104

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Deskstar T7K500 Hard Disk Drive Specification
104
10.17.5
Read Continuous bit
If the Read Continuous bit is set to one for the command, the device shall transfer the requested amount of data to
the host within the Command Completion Time Limit even if an error occurs.
The data sent to the host by the device
in an error condition is vendor specific.
10.17.6
Write Continuous bit
If the Write Continuous bit is set to one for the command, and an error is encountered, the device shall complete the
request without posting an error.
If an error cannot be resolved within the Command Completion Time Limit, the
erroneous section on the media may be unchanged or may contain undefined data.
A future read of this area may
not report an error, even though the data is erroneous.
10.17.7
Handle Streaming Error bit
The Handle Streaming Error bit specifies to the device that this command starts at the LBA of a recently reported
error section, so the device may attempt to continue its corresponding error recovery sequence where it left off
earlier.
This mechanism allows the host to schedule error recovery and defect management for content critical data.
10.17.8
Streaming Logs
The Streaming Data Transfer feature set requires two error logs and one performance log.
These logs are accessed
via the Read Log Ext command; the information included in the error logs is volatile and is not maintained across
power cycles, hard resets, or sleep.
These error logs are 512 bytes in length and retain the last 31 errors that occurred
during any Streaming Data transfer.
10.18
SCT Command Transport Feature Set
SMART Command Transport (SCT) is the method for the drive to receive commands using log page E0h and
transporting data using log page E1h. These log pages are used as follows:
There are two ways to access the log pages: using SMART READ/WRITE LOG and READ/WRITE LOG EXT.
Both sets of commands access the same log pages and provide the same capabilities.
The log directory for log pages E0h and E1h should report a length of one. The length of log page E1h does not
indicate the length of an SCT data transfer.
If SMART is supported, but not enabled, the drive supports SMART READ/WRITE LOG for Log page E0h and
E1h.
If security is enabled and password has not been issued to unlock the device, all SCT commands will fail.
Log page E0h
Log page E1h
Write log page
Issue Command
Send Data to the drive
Read log page
Return Status
Received Data from the drive