Write Buffer - IBM Ultrium Internal Tape Drive T200 Reference Manual

WRITE BUFFER

The WRITE BUFFER command transfers data into the memory on the drive for the
purpose of diagnostics, tests, or firmware upgrade.
If the Mode field is 000b, then the data to be written is sent with a 4-byte header,
which must be set to all zeroes. If the Mode field is 010b, then just the data to be
written is sent.
The Buffer ID field indicates which buffer is to be written.
To download firmware, Modes 100b, 101b, 110b, and 111b are accepted and
handled in the same fashion. Any Buffer ID value in these modes is allowed and
ignored. The code must be downloaded with strictly increasing offsets. If it is not, no
data is written and Check Condition status is generated. The Sense Key is set to
Illegal Request (5) and the ASC/ASCQ is set to Invalid Field in CDB (2400). Ending
status is given when the code has been successfully saved to flash, but before the
drive has initiated its reset.
The Buffer Offset field indicates where in the buffer the data should be written. This
must be smaller than the size of the buffer.
The Parameter List Length field holds the amount of data. This must be smaller
than the difference between the Buffer Offset field and the size of the buffer. If it is
not, no data is written and Check Condition status is generated. The Sense Key is
set to Illegal Request (5) and the ASC/ASCQ is set to Invalid Field in CDB (2400).
Buffers that may be written to are Test, Firmware, and VPD (see "READ BUFFER"
on page 49).
Table 107. WRITE BUFFER Command
7 6
0
1 Logical Unit Number (0)
2
3
:
5
6
:
8
9
5 4 3
Operation Code (3Bh)
Reserved
Buffer ID
Buffer Offset
Parameter List Length
Control
Chapter 2. Command Support
2 1 0
Mode
85