Hitachi HTS548040M9AT00 Specifications page 175

S.M.A.R.T.—either enabled or disabled—will be preserved by the device across power cycles. Once enabled, the
receipt of subsequent S.M.A.R.T. Enable Operations subcommands will not affect any of the Attribute Values.
Upon receipt of the S.M.A.R.T. Enable Operations subcommand from the host, the device asserts BSY, enables
S.M.A.R.T. capabilities and functions, clears BSY, and asserts INTRQ.
13.38.1.9 S.M.A.R.T. Disable Operations (subcommand D9h)
This subcommand disables all S.M.A.R.T. capabilities within the device including the device's attribute auto save
feature. After receipt of this subcommand the device disables all S.M.A.R.T. operations. Non self-preserved
Attribute Values will no longer be monitored. The state of S.M.A.R.T.—either enabled or disabled—is preserved
by the device across power cycles. Note that this subcommand does not preclude the device's power mode attribute
auto saving.
Upon receipt of the S.M.A.R.T. Disable Operations subcommand from the host, the device asserts BSY, disables
S.M.A.R.T. capabilities and functions, clears BSY, and asserts INTRQ.
After receipt of the device of the S.M.A.R.T. Disable Operations subcommand from the host, all other S.M.A.R.T.
subcommands—with the exception of S.M.A.R.T. Enable Operations—are disabled, and invalid and will be
aborted by the device—including the S.M.A.R.T. Disable Operations subcommand— returning the error code as
specified in Table 119: "S.M.A.R.T. Error Codes" on page 170.
Any Attribute Values accumulated and saved to volatile memory prior to receipt of the S.M.A.R.T. Disable Opera-
tions command will be preserved in the device's Attribute Data Sectors. If the device is re-enabled, these Attribute
Values will be updated, as needed, upon receipt of a S.M.A.R.T. Read Attribute Values or a S.M.A.R.T. Save
Attribute Values command.
13.38.1.10 S.M.A.R.T. Return Status (subcommand DAh)
This subcommand is used to communicate the reliability status of the device to the host's request. Upon receipt of
the S.M.A.R.T. 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.
13.38.1.11 S.M.A.R.T. Enable/Disable Automatic Off-line (subcommand 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. This subcommand 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 dis-
abled. This subcommand also enables and disables the off-line read scanning feature that cause the device to per-
form the entire read scanning with defect reallocation as the part of the off-line data collection activities.
Travelstar 5K80 Hard Disk Drive Specification
159