IBM Ultrastar 36LZX, Specifications

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8.42.3 Download Microcode (Mode 0100b)
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 follow-
ing Buffer IDs are supported by the Target:
- 00h : Main Microprocessor Code
- 81h : Reserved Area Data
Any other value for the Buffer ID will cause the command to terminate with CHECK CONDITION status.
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. 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.
This process generates a unit attention condition for MICROCODE HAS BEEN CHANGED for all initi-
ators except the one which sent the write buffer command. Upon the completion of the write buffer com-
mand 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 develop-
ment. 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.
Note: If the write buffer command with this mode is executed and the invalid code is downloaded, then it
is to be expected that the drive will never be complete or hang up the subsequent command. This con-
dition is normally recoverable by a power on/off cycle, but there is no guarantee of it.
8.42.4 Download Microcode and Save (Mode 0101b)
In this mode the data is transferred to the drive to save into the System reserved area on the disk. This is
for functional upgrade and configuration change reflecting the user's requirements and/or the manu-
facturer's reason, and it is stored in the media as a permanent copy. The newly downloaded code
becomes effective after the drive issues and completes a self-initiated Power On Reset.
Note: It requires up to 30 seconds to update the microcode including the Flash ROM update.
Note: New code to be downloaded to the drive will be provided by development either by request of a
customer for an additional function or as a result of a functional change by development. However
please note that not all possible fixes or new functions can be applied to a drive in this manner and that
there is a very high dependency on the level of ROM code contained within the drive. If an invalid code
or a code not compatible with the ROM code is downloaded, the drive will usually reject this code and
will continue normal operation. However there is a small possibility that an invalid code will be accepted.
If this occurs, the unit usually becomes inoperable and will have to be returned to the manufacturer for
recovery.
Ultrastar 36LZX hard disk drive specifications
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