User's Manual

DLT2000 SCSI Interface
DLT2000/DLT2700 Cartridge Tape Subsystem 8-127
8.4.26.1 Header and Data Mode
The data to be transferred is preceded by a 4-byte header consisting entirely of reserved
bytes. This header is discarded (not stored into the buffer). The buffer offset field must
be zero for this mode.
8.4.26.2 Write Data
Similar to mode 000b, except there is no header in the data passed to the target. The
Buffer Offset must be zero. Potential buffer overruns are detected and the command is
rejected.
8.4.26.3 Download Microcode
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.
The tape drive must be empty to allow downloading of an image. This is to safeguard
against accidentally starting a firmware update. If a cartridge is loaded when all or part
of a firmware image has been downloaded, another WRITE BUFFER with Download
mode will be rejected. Overlapping or nonconsecutive downloading of the image data is
not supported. The firmware image must be downloaded in integral multiples of 4K
bytes.
Any error on a Write Buffer command causes any downloaded image data to be
discarded, and the download must be restarted from the beginning.
8.4.26.4 Download Microcode and Save
This mode can be used to download and save the entire image at once, or to download
the image data and save it, or to cause a save operation after all the image data has been
downloaded using the Download only mode. This mode of the command causes the
image data to be verified and the Flash EEPROM firmware area to be updated. During
the reprogramming, the Write Protect and Drive Activity LEDS on the drive's front
panel will blink.