104 Product Manual - Disc Drive SCSI-2/SCSI-3 Interface (Vol. 2; Ver. 2), Rev. E
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Notes.
[1] LUN must be zero
[2] The mode field is defined in the following table and in the referenced sections.
DB2
DB1
DB0
Mode Definition
0
0
0
Write combined header and data (section 5.1.2.3.1)
0
1
0
Write data (section 5.1.2.3.2)
1
0
1
Download microcode and save (section 5.1.2.3.3)
[3]
See paragraph 5.1.2.3.1, 5.1.2.3.2 and 5.1.2.3.3
[4]
See “Control Byte” paragraph 4.2.6.
[5][6]
Not implemented by drives supported by this manual. Should be zeros.
5.1.2.3.1
Combined Header and Data Mode (000b)
In this mode, data to be written to the disc drives data buffer is preceded by a four byte header.
The Byte Transfer Length includes a four byte header and the Write Buffer data [1]. A transfer length of zero
indicates that no data transfer shall take place. This condition shall not create the Check Condition status. If
the transfer length is greater than the Buffer Capacity reported by the Read Buffer header, the disc drive shall
create the Check Condition status with the Sense Key of Illegal Request. In this case no data shall be
transferred from the initiator.
It shall not be considered an error to request a transfer length less than the Buffer Capacity.
The write data following the Write Buffer CDB consists of a 4 byte write buffer header (which always precedes
the data) plus the data to be written to the data buffer as follows:
Table 5.1.2-2. Write Buffer Header
Bit 7
6
5
4
3
2
1
0
Byte(s)
0 0
0
0
0
0
0
0
0
1 0
0
0
0
0
0
0
0
2 0
0
0
0
0
0
0
0
3 0
0
0
0
0
0
0
0
4 - n
Data To Be Written Into Disc Drive Buffer
Notes.
[1] See individual Product Manual table of SCSI INTERFACE COMMANDS SUPPORTED (Sec. 11.3) for
size of buffer.
