User Manual

SCSI Commands Reference Manual, Rev. J 266
www.seagate.com Direct Access Block commands (SPC-5 and SBC-4)
3.70.2 Combined header and data mode (00h)
NOTE This mode is not recommended.
In this mode, data to be transferred is preceded by a four-byte header. The four-byte header consists of all reserved bytes. The
BUFFER ID and the BUFFER OFFSET fields shall be zero.
The MODE SPECIFIC field is reserved.
The PARAMETER LIST LENGTH field specifies the maximum number of bytes that shall be transferred from the Data-Out Buffer.
This number includes four bytes of header, so the data length to be stored in the device server’s buffer is parameter list length
minus four. The application client should attempt to ensure that the parameter list length is not greater than four plus the
BUFFER CAPACITY field value (see table 106) that is returned in the header of the READ BUFFER command (mode 0h). If the
parameter list length exceeds the buffer capacity, the command shall be terminated with CHECK CONDITION status, with the
sense key set to ILLEGAL REQUEST, and the additional sense code set to INVALID FIELD IN CDB.
3.70.3 Vendor specific mode (01h)
This mode is not supported by Seagate products. If used, the drive will return CHECK CONDITION and report an ILLEGAL
REQUEST/INVALID FIELD IN CDB error.
3.70.4 Data mode (02h)
In this mode, the Data-Out Buffer contains buffer data destined for the logical unit. The BUFFER ID field identifies a specific buffer
within the logical unit. Seagate assigns buffer ID codes to buffers within the logical unit. Buffer ID zero shall be supported. If
more than one buffer is supported, then additional buffer ID codes shall be assigned contiguously, beginning with one. If an
unsupported buffer ID code is selected, the command shall be terminated with CHECK CONDITION status, with the sense key set
to ILLEGAL REQUEST, and the additional sense code set to INVALID FIELD IN CDB.
The MODE SPECIFIC field is reserved.
Data are written to the logical unit buffer starting at the location specified by the
BUFFER OFFSET field. The application client should
conform to the offset boundary requirements returned in the READ BUFFER descriptor. If the device server is unable to accept
the specified buffer offset, the command shall be terminated with CHECK CONDITION status, with the sense key set to ILLEGAL
REQUEST, and the additional sense code set to INVALID FIELD IN CDB.
The PARAMETER LIST LENGTH field specifies the maximum number of bytes that shall be transferred from the Data-Out Buffer to
be stored in the specified buffer beginning at the buffer offset. The application client should attempt to ensure that the
parameter list length plus the buffer offset does not exceed the capacity of the specified buffer. The capacity of the buffer is
indicated by the BUFFER CAPACITY field in the READ BUFFER descriptor (see table 106). If the BUFFER OFFSET and PARAMETER
LIST LENGTH fields specify a transfer in excess of the buffer capacity, the command shall be terminated with CHECK CONDITION
status, with the sense key set to ILLEGAL REQUEST, and the additional sense code set to INVALID FIELD IN CDB.
3.70.5 Download microcode and activate mode (04h)
In this mode, microcode shall be transferred to the device server and activated (see SPC-5).
The MODE SPECIFIC field is reserved.
The BUFFER ID field, BUFFER OFFSET field, and PARAMETER LIST LENGTH field are vendor specific.
3.70.6 Download microcode, save, and activate mode (05h)
In this mode, microcode shall be transferred to the device server, saved to nonvolatile storage, and activated (see 5.4) based on
the setting of the ACTIVATE MICROCODE field in the Extended INQUIRY VPD page (see 5.4.9).
The MODE SPECIFIC field is reserved.
The BUFFER ID field, BUFFER OFFSET field, and PARAMETER LIST LENGTH field are vendor specific.