Write buffer (3bh), Write data mode, Write – Dell PowerVault TL2000 User Manual
Page 98: Buffer, 3bh), Data, Mode
WRITE
BUFFER
(3Bh)
Write
Buffer
is
used
with
Read
Buffer
as
a
diagnostic
function
for
testing
the
device
data
buffer,
DMA
engine,
SCSI
bus
interface
hardware,
and
SCSI
bus
integrity.
Additional
modes
are
provided
for
downloading
and
saving
micro
code
and
updating
Vendor
Unique
settings.
Bit
7
6
5
4
3
2
1
0
Byte
0
Operation
Code
(3Bh)
1
LUN
Reserved
Mode
2
Buffer
ID
3
(MSB)
4
Buffer
offset
5
(LSB)
6
(MSB)
7
Parameter
list
length
8
(LSB)
9
Control
Field
descriptions:
Mode:
The
Mode
field
is
used
to
select
the
mode
of
operation.
The
media
changer
supports
the
following
values
within
this
field.
0010b
Data
0100b
Download
microcode
0101b
Download
microcode
and
save
1010b
Echo
buffer
If
any
non
supported
value
is
set,
the
media
changer
terminates
the
command
with
a
Check
Condition
status.
The
sense
key
will
be
set
to
ILLEGAL
REQUEST
and
the
sense
data
to
INVALID
FIELD
IN
CDB.
Buffer
ID:
When
the
Mode
is
set
to
Download
micro
code
or
Download
micro
code
and
save,
the
Buffer
ID
should
be
set
to
zero.
When
the
mode
is
set
to
Vendor
Unique
operation,
the
Buffer
ID
indicates
the
requested
page
to
update.
If
the
value
of
the
Buffer
ID
is
not
supported
by
the
specified
Mode
the
command
is
rejected.
The
target
detects
and
rejects
commands
that
would
overrun
the
buffer.
Buffer
Offset:
The
Buffer
Offset
is
required
for
the
Download
micro
code
(and
save)
modes
and
optional
for
the
Vendor
Unique
and
Data
modes.
In
all
other
modes
the
Buffer
Offset
must
be
set
to
zero.
Write
Data
Mode
With
this
mode,
SCSI
bus
integrity
can
be
tested
in
conjunction
with
the
READ
BUFFER
command.
The
host
can
by
means
of
this
mode
send
up
to
256
bytes
to
the
media
changer.
This
data
can
be
retrieved
by
means
of
the
READ
BUFFER
command.
The
Buffer
Offset
specifies
the
offset
within
the
buffer.
Potential
buffer
overruns
are
detected
and
will
result
into
a
Check
Condition
the
sense
key
will
be
set
to
ILLEGAL
REQUEST
and
the
additional
sense
data
to
INVALID
FIELD
IN
CDB.
3-84
TL2000
and
TL4000
SCSI
Reference