Technical information

HGST Ultrastar C15K600 Hard Disk Drive Specification
286
18.59
WRITE BUFFER (3B)
Table 265 WRITE BUFFER (3B)
Byte
Bit
7
6
5
4
3
2
1
0
0
Command Code = 3Bh
1
Mode Specific
Mode
2
Buffer ID
3-5
Buffer Offset
6-8
Parameter List Length
9
VU = 0
Reserved = 0
FLAG
LINK
The WRITE BUFFER command is used in conjunction with the READ BUFFER command as a diagnostic function
for testing the memory of the drive and the SCSI bus integrity. This command does not alter the medium of the drive.
Additional modes are provided for downloading microcode and saving microcode.
This command will cause the entire cache to be emptied.
The function of this command and the meaning of fields within the command descriptor block depend on the
contents of the mode field.
If any values other than shown above are specified, Check Condition status is returned with a sense key of Illegal
Request and additional sense code of Invalid Field in CDB.
MOD Description
00000 Write combined header and data
00010 Data
00100 Download Microcode
00101 Download Microcode and Save - single binary file
00111 Download Microcode and Save - multiple binary files
01010 Write Data to Echo Buffer
01101
Download microcode with offsets, select activation events,
save, and defer activate
01110 Download microcode with offsets, save, and defer activate
01111 Activate deferred microcode
11010 Enable expander Communications Protocol
All Others Not Supported