Write Combined Header And Data Mode (000B); Write Data Mode (010B); Download Microcode Mode (100B) - Quantum DLT 8000 Product Manual

SCSI Commands
WRITE BUFFER Command (3Bh) (continued)
Table 5–102 WRITE BUFFER Command Data — Field Descriptions (continued)
Field Name
Buffer ID
Buffer Offset

5.32.1 Write Combined Header and Data Mode (000b)

The data to be transferred is preceded by a 4-byte header consisting entirely of reserved
bytes. This header is discarded (not stored within the buffer).
The buffer offset field must be 0 for this mode.

5.32.2 Write Data Mode (010b)

Similar to Header and Data Mode, except there is no header in the data passed to the
target. Any potential buffer overruns are detected and the command is rejected.
During the actual reprogramming of the FLASH EEPROM, if any type of powerfail
occurs, or if the reprogramming fails before completion, the tape drive subsystem
becomes unusable and the tape drive must be replaced.

5.32.3 Download Microcode Mode (100b)

Using buffer offsets, the host can download the firmware image into the target's buffer
in pieces. These commands do not cause the new image to become active. A Download
and Save Mode WRITE BUFFER command must be issued for the image to become
active.
5-224
Description
For all of the modes described for the Mode field, only a Buffer ID of
0 is supported. If the Buffer ID field is a value other than 0, the
command is rejected. The target detects and rejects commands that
would overrun the buffer.
See Sections 5.32.1 through 5.32.4 for the appropriate settings.
CAUTION
Quantum DLT 8000 Tape System