C141-E039-01EN
1 - 13
1.3.3
Disconnect/Reconnect Processing
When processing is performed by the TARG during the command execution process which
does not require operation on the SCSI bus, the TARG temporarily returns the SCSI bus to the
BUS FREE phase by disconnect processing, making it possible for the TARG to execute the
command internally. Through this function, the INIT is enabled to process multiple
commands on the SCSI bus.
(1)
Conditions where disconnects are permitted and commands which are the object of
disconnect processing
If all of the conditions shown below for permitting a disconnect are satisfied, the IDD executes
disconnect processing. However, As shown in Table 1.2, disconnect processing may be valid
or invalid, and the disconnect processing execution timing may differ, depending on the type
of command.
Conditions for Permitting a Disconnect
1) The SCSI ID of the INIT is notified in the SELECTION phase.
2) The INIT generates the ATTENTION condition in the selection phase.
3) The INIT notifies the TARG that disconnect processing is permitted by an IDENTIFY
message.