Hitachi ULTRASTAR 15K450 HUS154530VLF400 - Manual (Page 312)

Hitachi Ultrastar 15K450 (FC-AL) Hard Disk Drive Specification
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19.59.3 Download Microcode (Mode 00100b)
NOTE: It is not expected that a customer will ever issue this format of the command.
In this mode, the microcode is transferred to the control memory space of the drive. When downloaded, the drive will operate
with the newly downloaded code immediately until the next power cycle.
Buffer ID field is used to indicate which portion of the microcode image is being downloaded. The following Buffer IDs are
supported by the Target:
- 00h: Main Microprocessor Code
- nnh : ID of Vendor Unique Reserved Area
Any unsupported value for the Buffer ID will cause the command to terminate with Check Condition status. And the drive
shall set the sense key to Illegal Request and additional sense code to Illegal Field In CDB.
Buffer Offset must be zero. If an invalid value is specified, the command is terminated with Check Condition status. The
drive shall set the sense key to Illegal Request and additional sense code to Illegal Field in CDB.
Parameter List Length must be the size of the data set to be downloaded. It may also be set to 0000h in which case no code
is updated and command status is returned. If an invalid value is specified, the command is terminated with Check Condition
status. And the drive shall set the sense key to Illegal Request and additional sense code to Illegal Field In CDB.
This process generates a unit attention condition for MICROCODE HAS BEEN CHANGED for all Initiators except the one
which sent the WRITE BUFFER command. Upon the completion of the WRITE BUFFER command the new microcode is
immediately ready for operation.
Note: The Download Microcode mode described in this specification is to indicate that the drive will accept a command with
this mode, though it is not expected that a user will ever issue such a command. To use the write buffer command with this
mode, a special microcode version is required from development. If such a microcode is released from development, then it
will include appropriate instructions on the function of new microcode and its effect on the drive operations after download.