ADLINK ASD8P-MT1 Series - Manual (Page 37)

ASD8P-MT1 Specification Page 37 of 43
SMART READ LOG SECTOR (Code DAh)
This subcommand is used to communicate the reliability status of the device to the host's request.
Upon receipt of the SMART Return Status subcommand the device asserts BSY, saves any
updated Attribute Values to the reserved sector, and compares the updated Attribute Values to the
Attribute Thresholds.
If the device does not detect a Threshold Exceeded Condition, or detects a Threshold Exceeded
Condition but involving attributes are advisory, the device loads 4Fh into the LBA Mid register, C2h
into the LBA High register, clears BSY, and asserts INTRQ. If the device detects a Threshold
Exceeded Condition for prefailure attributes, the device loads F4h into the LBA Mid register, 2Ch
into the LBA High register, clears BSY, and asserts INTRQ. Advisory attributes never result in a
negative reliability condition.
SMART READ LOG SECTOR (Code DBh)
This subcommand enables and disables the optional feature that cause the device to perform the
set of off-line data collection activities that automatically collect attribute data in an off-line mode
and then save this data to the device's nonvolatile memory. It may either cause the device to
automatically initiate or resume performance of its off-line data collection activities or cause the
automatic off-line data collection feature to be disabled. It also enables and disables the off-line
read scanning feature that cause the device to perform the entire read scanning with defect
reallocation as the part of the off-line data collection activities.
Device's Sector Count of XXh written by the host before issuing SMART READ LOG SECTOR
command shall be set to specify the feature to be enabled or disabled:
- XXh = 00h: The automatic off-line data collection feature will be disabled- Disabling this
feature does not preclude the device from saving attribute values to nonvolatile memory
during some other normal operation such as during a power-on, during a power-off
sequence, or during an error recovery sequence.
- XXh = F8h: The automatic Off-line data collection feature will be enabled.
The table below lists the SMART commands.
Table 15 SMART commands
Subcommand Code LBA Low value
SMART ATTRIBUTE VALUES (READ DATA) D0h
READ ATTRIBUTE THRESHOLDS D1h
ENABLE/DISABLE ATTRIBUTE AUTOSAVE D2h
SAVE ATTRIBUTE VALUES D3h