User Manual

SCSI Commands Reference Manual, Rev. J 144
www.seagate.com Direct Access Block commands (SPC-5 and SBC-4)
3.20 READ BUFFER (10) command
3.20.1 READ BUFFER (10) command introduction
The READ BUFFER (10) command (see table 103) is used in conjunction with the WRITE BUFFER command as a diagnostic
function for testing memory in the SCSI device and the integrity of the service delivery subsystem. This command shall not alter
the medium.
MODE SPECIFIC field
The usage of the MODE SPECIFIC field depends on the value in the MODE field.
MODE field
The function of this command and the meaning of fields within the CDB depend on the contents of the MODE field. The MODE field is defined in
table 104.
Table 103 READ BUFFER (10) command
Bit
Byte
7 6 5 4 3 2 1 0
0 OPERATION CODE (3Ch)
1 MODE SPECIFIC MODE
2 BUFFER ID
3 (MSB)
BUFFER OFFSET. . .
5 (LSB)
6 (MSB)
ALLOCATION LENGTH. . .
8 (LSB)
9 CONTROL
Table 104 MODE field
MODE Description
00h
Combined header and data
[a]
01h
Not supported
[a]
02h
Data
03h
Descriptor
04h - 09h
Reserved
0Ah
Echo buffer
0Bh
Echo buffer descriptor
0Ch - 19h
Reserved
1Ah
Obsolete
1Bh
Reserved
1Ch
Error history
1Dh - 1Fh
Reserved
[a] Mode 00h and 01h are not recommended.