August 30, 1990 To: X3T9.2 Committee From: John Lohmeyer, NCR Principal Member of X3T9.2 Subject: SCSI-3 Modifications to Outbound DISCONNECT Message At the August '90 plenary meeting, I was asked to document the interaction of the outbound DISCONNECT message with the TARGET TRANSFER DISABLE message which was accepted for SCSI-3 in document X3T9.2/90-062R4. I propose that we modify the outbound DISCONNECT message in SCSI-3 as shown in this document. Changes are shown with a "|" in the left margin. 5.6.6. DISCONNECT | Optionally, this message may also be sent from an initiator to a target to |instruct the target to disconnect from the SCSI bus. If this outbound |disconnect option is supported, and after the DISCONNECT message is received, the target shall switch to MESSAGE IN phase, send the DISCONNECT message to the initiator (possibly preceded by SAVE DATA POINTER message), and then disconnect by releasing BSY. After releasing the BSY signal: | (1) If no TARGET TRANSFER DISABLE message has been received for this I/O |process, the target shall not participate in another ARBITRATION phase for at least a disconnection delay. | (2) If a TARGET TRANSFER DISABLE message has been received for this I/O |process, the target shall not reconnect for the I/O process. The initiator |may reconnect to the I/O process as described in the CONTINUE I/O PROCESS |message (see 5.6._). |If the outbound disconnect option is not supported or the target cannot disconnect at the time when it receives the DISCONNECT message from the initiator, the target shall respond by sending a MESSAGE REJECT message to the initiator.