Write Buffer (3B) - IBM Ultrastar 36LZX Specifications

8.42 WRITE BUFFER (3B)

Byte
7 6
0
1 Reserved = 0
2
3 (MSB)
4
5
6 (MSB)
7
8
9 VU = 0
Figure 160. WRITE BUFFER (3B)
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 for
downloading 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.
MODE Description
0000 Write combined header and data
0010 Data
0100 Download Microcode
0101 Download Microcode and Save
1010 Write Data to Echo Buffer
No other modes are supported by the drive.
Bit
5 4 3
Command Code = 3Bh
Buffer ID
Buffer Offset
Parameter List Length
Reserved = 0
Ultrastar 36LZX hard disk drive specifications
2 1 0
Mode
(LSB)
(LSB)
FLAG LINK
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