Sony AIT-SDX460, Руководство по техническим характеристикам продукции

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7. ATAPI Packet Command Specification WRITE BUFFER
SONY AIT-1Turbo drive SDX-460V series Ver.1.0 7-80
7.26. WRITE BUFFER 3Bh
Bit
Byte
7 6 5 4 3 2 1 0
0 Operation Code (3Bh)
1 Reserved Mode
2 Buffer ID
3 (MSB)
4
5
Buffer Offset
(LSB)
6 (MSB)
7
8
Parameter List Length
(LSB)
9 Reserved
10 Reserved
11 Reserved
WRITE BUFFER is used in conjunction with the READ BUFFER command as a diagnostic function for testing the
buffer and 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. This command is provided for
downloading firmware .
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.
Table 7-16: Write Buffer Mode Field
Mode Description
000b Write Combined Header and Data
010b Write Data
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 TRANSFER. This number includes four bytes
of header, so the data length to be stored in the buffer is transfer length minus four. The host 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.