Write Data To Echo Buffer (1010B) - Seagate Ultra160 Product Manual

320 SCSI Interface Product Manual, Rev. B
and save operation. In this mode, the Data Out Buffer contains vendor-specific, self-describing microcode or
control information.
Since the downloaded microcode or control information may be sent using several commands, when the logi-
cal unit detects the last download microcode with offsets and save mode WRITE BUFFER command has been
received, the device server shall perform any logical unit required verification of the complete set of down-
loaded microcode or control information prior to returning Good status for the last command. After the last
command completes successfully the device server shall generate a unit attention condition (see SAM-2) for all
initiators except the one that issued the set of WRITE BUFFER commands. When reporting the unit attention
condition, the device server shall set the additional sense code to Microcode Has Been Changed.
If the complete set of WRITE BUFFER commands required to effect a microcode or control information change
(one or more commands) are not received before a reset or power-on cycle occurs, the change shall not be
effective and the new microcode or control information shall be discarded.
The Buffer ID field identifies a specific buffer within the logical unit. The vendor assigns buffer ID codes to buff-
ers within the logical unit. A Buffer ID value of zero shall be supported. If more than one buffer is supported,
additional buffer ID codes shall be assigned contiguously, beginning with one. If an unsupported buffer ID code
is identified, the device server shall return CHECK CONDITION status and shall set the sense key to ILLEGAL
REQUEST with an additional sense code of Invalid Field In CDB.
The microcode or control information are written to the logical unit buffer starting at the location specified by the
Buffer Offset field. The application client shall conform to the offset boundary requirements. If the device server
is unable to accept the specified buffer offset, it shall return CHECK CONDITION status and it shall set the
sense key to ILLEGAL REQUEST with an additional sense code of Invalid Field In CDB.
The PARAMETER LIST LENGTH field specifies the maximum number of bytes that shall be present in 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 may be determined by the Buffer Capacity field in the READ
BUFFER descriptor.) If the Buffer Offset and PARAMETER LIST LENGTH fields specify a transfer in excess of
the buffer capacity, the device server shall return CHECK CONDITION status and shall set the sense key to
ILLEGAL REQUEST with an additional sense code of Invalid Field In CDB.
8.58.8

Write data to echo buffer (1010b)

In this mode the device server transfers data from the application client and stores it in an echo buffer. An echo
buffer is assigned in the same manner by the target as it would for a write operation. Data shall be sent aligned
on four-byte boundaries. The Buffer ID and Buffer Offset fields are ignored in this mode. Upon successful com-
pletion of a WRITE BUFFER command the data shall be preserved in the echo buffer unless there is an inter-
vening command to any logical unit in which case it may be changed.