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| Chapter 8 Details of Usage |
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| Target Mode Usage and SCSI Protocol Handling |
Simple Queue Tag (2 bytes) - This message revives a I_T_L_Q nexus for a disconnected I/O process. It will be sent by the adapter immediately following the Identify message. The host will send the Simple Queue Tag on all Target Mode Response commands that are caused by a Target Mode selection that used Queued Tagging. The adapter will send this specified message whenever it must reselect the initiator during the processing of the Response command.
Restore Pointers - Directs the initiator to copy the most recently saved command, data, and status pointers for the I/O process to the corresponding active pointers. This message must be sent in a Target Mode Response command with no data transfer specified.
Status or Message Sequences Sent to the Initiator (by the Adapter)
The following descriptions include all of the status/message sequences that may be sent to the initiator by the adapter.
Busy Status Byte and Command Complete Message Byte - This sequence is sent if the adapter is selected by an initiator and the host has not enabled the Target Mode. This should inform the initiator to try again later.
Disconnect Message Byte - The disconnect message is sent just before going to the Bus Free phase after a command descriptor block is received. The adapter always disconnects (if allowed by the Identify message) to free the SCSI bus while the command is being processed by the host.
Identify - This message will be sent to the initiator as part of a reselection sequence. The LUN field of the response command will be used to supply the LUNTRN field of this message.
Message Reject - This message is sent whenever the adapter receives a message that is not allowed.
Restore Pointers - This message will be used to retry either detected parity errors or Initiator Detected Errors. This message is sent during data transfers, status phase, and command phase.
Synchronous Data Transfer Request (5 bytes) - This message will be sent to the initiator in response to a Synchronous Data Transfer Request received from the initiator, or to initiate a Synchronous Data Transfer negotiation.
Wide Data Transfer Request (4 bytes) - This message will be sent to the initiator in response to a Wide Data Transfer Request received from the initiator, or to initiate a Wide Data Transfer negotiation.
21020285 D | User’s Guide |
