Figure 122. Individual Threshold Data Structure - IBM IC25N020ATDA04 - Travelstar 20 GB Hard Drive Specifications

13.33.3.2 Individual Thresholds Data Structure
The following defines the 12 bytes that make up the information for each Threshold entry in the Device
Attribute Thresholds Data Structure. Attribute entries in the Individual Threshold Data Structure are in the
same order and correspond to the entries in the Individual Attribute Data Structure.
Description
Attribute ID Number (01h to FFh)
Attribute Threshold (for comparison with Attribute
Values from 00h to FFh)
00h – "always passing" threshold value to be used
for code test purposes
01h – minimum value for normal operation
FDh – maximum value for normal operation
FEh – invalid for threshold value
FFh – "always failing" threshold value to be
used for code test purposes
Reserved (00h)
Total Bytes

Figure 122. Individual Threshold Data Structure

13.33.3.3 Attribute ID Numbers
Attribute ID Numbers supported by the device are the same as Attribute Values Data Structures.
13.33.3.4 Attribute Threshold
These values are preset at the factory and are not meant to be changeable. However, the host might use
the "S.M.A.R.T. Write Attribute Threshold" subcommand to override these preset values in the Threshold
sectors.
13.33.3.5 Data Structure Checksum
The Data Structure Checksum is the 2's compliment of the result of a simple 8-bit addition of the first
511 bytes in the data structure.
Travelstar 48GH, 30GN & 15GN hard disk drive specifications
Byte
180
Offset Format
1 00h binary
1 01h binary
10 02h binary
12