User manual

Hitachi hard disk drive specifications
153
11.18.5 Read Stream Error log
Table 109 defines the format of the Read Stream Error log. Entries are placed into the Read Stream Error log
only when the SE bit is set to one in the Status Register. The 512 bytes returned shall contain a maximum of
31 error entries. The Read Stream Error Count shall contain the total number of Read Stream Errors detected
since the last successful completion of the Read Log Ext command with LBA Low register set to 22h. This
error count may be greater than 31, but only the most recent 31 errors are represented by entries in the log. If
the Read Stream Error Count reaches the maximum value that can be represented after the next error is
detected the Read Stream Error Count shall remain at the maximum value. After successful completion of a
Read Log Ext command with the LBA Low Register set to 22h, the Read Stream Error Log shall be reset to a
power-on or hardware reset condition, with the Error Log Index and Read Stream Error Count cleared to zero.
The Read Stream Error Log is not preserved across power cycles and hardware reset.
Description
Bytes
Offset
Structure Version
1
00h
Error Log Index
1
01h
Read Stream Error Log Count
2
02h
Reserved
12
04h
Read Stream Error Log Entry #1
16
10h
Read Stream Error Log Entry #2
16
20h
...
Read Stream Error Log Entry #31
16
1F0h
512
Table 109 Read Stream Error Log
The Data Structure Version field shall contain a value of 02h indicating the second revision of the structure
format.
The Read Stream Error Log Count field shall contain the number of uncorrected sector entries currently
reportable to the host. This value may exceed 31.
The Error Log Index indicates the error log data structure representing the most recent error. Only values
(31:1) are valid.