SCSI Description
Table 5-5 contains a description of the CDB control field.
Command Descriptor Block Control Field-Field Descriptions
Table 5-5
Field
Description
Vendor Specific Bits
These bits must be 0.
NACA
Normal Auto-Contingent Allegiance - This bit must be zero to indicate that
SCSI-2 Contingent Allegiance rules apply.
Link Bit
A Link bit set to one signals that the initiator requests continuation of a task
(I/O Process) across two or more SCSI commands. If the Link bit is one and the
flag bit is zero, and the command completes successfully, the drive will contin-
ue the task and return a status of INTERMEDIATE and a service response of
Linked Command Complete.
If the Link bit and the Flag bit of the Control word are both set to one, and the
drive completes a command with a status of INTERMEDIATE, the drive will
return a service response of Linked Command Complete (with Flag). Refer to
Section 5.6 for Linked Commands description.
Flag Bit
The Flag bit is used in conjunction with the Link Bit to notify the initiator in an
expedient manner that a command has been completed. Aflag bit set to 1 is val-
id only when the Link Bit is set to 1.
5-6
Maxtor Atlas 15K