Quantum DLT 4700, Руководство по эксплуатации продукта

Страница: 286 / 360

DLT4000 SCSI Interface
8-126 DLT4000/DLT4500/DLT4700 Cartridge Tape Subsystem
8.4.26 WRITE BUFFER (3Bh)
Bit
7 6 5 4 3 2 1 0
0 Operation Code (3Bh)
1 Logical Unit Number Reserved Mode
2 Buffer ID (00h)
Byte 3 (MSB)
4 Buffer Offset (000000h)
5 (LSB)
6 (MSB)
7 Parameter List/Data Length
8 (LSB)
9 Unused Reserved Flag Link
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 Write combined header and data
010b Write data
100b Download Microcode
101b 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.
8.4.26.1 Header and Data Mode