User's Manual

DLT2000 SCSI Interface
8-126 DLT2000/DLT2700 Cartridge Tape Subsystem
8.4.26 WRITE BUFFER (3Bh)
Bit
76543210
0 Operation Code (3Bh)
Logical Unit Number Mode
Buffer ID (00h)
Byte (MSB)
Buffer Offset (000000h)
(LSB)
(MSB)
Parameter List/Data Length
Unused Link
Reserved1
Flag
(LSB)
Reserved
2
3
4
5
6
7
8
9
Figure 8-80 WRITE BUFFER CDB
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.
It is also used for downloading and updating controller microcode (firmware).
Mode
The drive supports the following values within the field. If any other value is set, the
drive terminates the command with a CHECK CONDITION status and an ILLEGAL
REQUEST sense key set.
Mode Description
000b
010b
100b
101b
Write combined header and data
Write data
Download Microcode
Download Microcode and Save
Figure 8-81 WRITE BUFFER Modes Supported
For all modes, only a Buffer ID of zero is supported. If the Buffer ID field is nonzero,
the command will be rejected. The target detects and rejects commands that would
overrun the buffer.