Seagate Ultra 320 ユーザーズマニュアル

118  

                                              

        Parallel SCSI Interface Product Manual, Rev. A

[1] See Table 49 for the format of the SPI L_Q information unit.
[2] See Table 54 for the format of the SPI Status information unit.
[3] See Figure 16.

The SPI command information unit (see Table 46) transfers CDBs, task attributes, and task management 
requests to be performed by a device server.

a SCSI initiator port shall consider a BUS FREE phase after the transfer of a SPI command information unit to 
be equivalent to receiving a DISCONNECT message.

If a SCSI target port does not have the resources to accept a SPI command information unit and the Task Man-
agement Flags

 

field equals 00h the target shall transfer all the bytes of the current SPI command information 

unit but need not hold the transmitted information. After transferring all the SPI command information unit bytes 
the target shall change to a DT DATA IN phase and transmit a SPI status information unit with the status 
defined in the SCSI Architecture Model-4 standard (SAM-4) for this condition. If the initiator has more com-
mands to send the target, the initiator shall wait at least until the next selection before those remaining com-
mands may be sent.

(always Targ to Init)

(logical reconnect)

(from SPI DATA 

or SPI COMMAND)

(from SPI DATA)

(always Targ to Init)

(to SPI L_Q/DATA [3])

(to QAS)

(physical

 disconnect)

(logical disconnect)

Attention

Condition

(data pointer

 restored)

[1]

[2]

Data
Length
= 0