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WRITE BUFFER
is used to transfer data into memory on the drive for the purposes of diagnostics, tests
Write Buffer
or firmware upgrade. The data is placed into one of the drive buffers depending on the Mode and
Buffer ID fields of the command.
CAUTION:
Do not attempt to use the buffer modifying functions of this command unless you
really know what you are doing. The buffer modifying functions are intended as a diagnostic
aid to be used in conjunction with the
the buffer so that it subsequently written to media because all host data is flushed before
executing the command.
The firmware download functions are intended for use by manufacturing and by customers using
upgrade utilities supplied by HP.
Pre-execution checks:
Illegal Field
Command descriptor block:
7
0
1
2
3
(MSB)
5
6
(MSB)
8
9
CDB fields:
Mode
This field can be set to one of the following values:
Read Buffer
Reservation
Deferred Error
6
5
Operation Code (3Bh)
Reserved (0)
Parameter List Length
00h
The drive transfers a 4-byte header from the host (which should be set to zeros),
followed by (allocation length
buffer identified by the Buffer ID, starting from offset zero in the buffer.
The Buffer ID and Buffer Offset must both be zero. Allocation Length must not
exceed (buffer size + 4).
02h
The drive transfers allocation length bytes of data from the host, bytes of data
which is placed in the buffer indicated by Buffer ID, starting from Buffer Offset
from the start of the buffer. No header is sent.
The Buffer Offset and Allocation Length must be kept within the buffer size, and
the Buffer ID must to set to one of the valid values.
command. It is not possible to modify data in
Unit Attention
4
3
2
Mode
Buffer ID
Buffer Offset
Control
4) bytes of data. The data is written into the
3Bh
1
0
(LSB)
(LSB)
WRITE BUFFER 3Bh 183
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