Write Buffer 3Bh - Sony AIT-SDX550 Product Specifications Manual

6.Command Specification

6.30. WRITE BUFFER 3Bh

Bit 7
Byte
0
1 Logical Unit Number
2
3 (MSB)
5
6 (MSB)
8
9 Unused (00b)
WRITE BUFFER is used in conjunction with the READ BUFFER command as a diagnostic function for testing the
buffer the SCSI bus integrity of the drive. A REWIND command should be sent to the drive after WRITE/READ
BUFFER diagnostic testing to allow normal operation.
WRITE BUFFER command is valid only when there is no tape inserted in the drive, or when the tape is positioned at
BOT. An attempt to issue the Write Buffer command when the tape is not at BOT will result in a CHECK CONDITION
status with a Request Sense Key of ILLEGAL REQUEST.
Note: The drive will write any buffered data to tape prior to executing this command. Any data that is then transferred
by the WRITE BUFFER is not written to tape.
Mode: The drive supports the following values within the Mode field. If any other value is set, the drive will terminate
the command with a CHECK CONDITION status and an ILLEGAL REQUEST sense key set.
Any Write Data, file-marks or set-marks in buffer will be transfer to tape before this command is executed.
Combined Header and Data Mode - in this mode, the test data to be transferred must be preceded by a four-byte
header. The four-byte header consists of all reserved bytes. The Parameters List Length specifies the maximum
number of bytes that will be transferred during the DATA OUT phase. This number includes four bytes of header, so
the data length to be stored in the buffer is transfer length minus four. The initiator should ensure that the transfer
length is not greater than four plus the available length that is returned in the header of the READ BUFFER
command.
Data Mode - in this mode, the DATA OUT phase contains only buffer test data.
Buffer ID: The supported values are:
If an unsupported Buffer ID code is requested, the drive returns a CHECK CONDITION status with an ILLEGAL
REQUEST sense key.
Buffer Offset: The buffer offset field contains the byte offset within the specified buffer from which data shall be
transferred to. The initiator should conform to the offset boundary requirements returned in the WRITE BUFFER
descriptor. If the target is unable to accept the specified buffer offset, it shall return CHECK CONDITION status, shall
set the Sense Key to ILLEGAL REQUEST, and set the Additional Sense Code to ILLEGAL FIELD IN CDB.
6-104
6 5 4
Operation Code (3Bh)
Reserved
Parameter List Length
Table 6-79: WRITE BUFFER Mode Field
Mode
0000b Write combined header and data
0010b Write data
1010b Echo Buffer
Buffer ID
0 Write Interface Buffer
1 Write Group Buffer
3 2
Buffer ID
Buffer Offset
Reserved
Description
Description
SONY AIT-2 Turbo drive SDX-550V series Ver.1.0
WRITE BUFFER
1 0
Mode
(LSB)
(LSB)
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