Ciprico Rimfire 3880 manual Target Routines, Parity error conditions, Message parity errors

	Chapter 8 Details of Usage
Page 8 - 14	Target Mode Usage and SCSI Protocol Handling

Parity error conditions

Target Routines

If a parity error is detected on incoming message bytes, the adapter will receive all of the remaining message bytes (until ATN is negated) and then request the message bytes again. During the retry, the state of the ATN line will not be monitored; it is required that the initiator respond correctly to this retry sequence.

If a parity error is detected on incoming command or data bytes, the adapter will stop the transfer and send a Restore Pointers message to the initiator. The transfer will then be restarted. Target Mode Response commands must include a Save Data Pointer message before disconnecting to ensure that this retry technique will work.

Message parity errors

If a Message Parity Error message is received from the initiator in response to a message sent to it, the adapter will return to the Message In phase and resend the entire message.

If a Message Parity Error message is received at any other time, the adapter will go to the Bus Free phase and report this illegal message to the host.

Initiator-detected Error messages

If an Initiator-detected Error message is received from the initiator right after a data transfer, the transfer will be halted and the Restore Pointers message will be sent to the initiator. The transfer will then be restarted. It is required that the host always send a Save Data Pointer message before disconnecting to ensure that this retry technique will work.

If an Initiator-detected Error message is received from the initiator right after the Status phase, the Restore Pointers message will be sent to the initiator. The status byte will then be resent.

If an Initiator-detected Error message is received from the initiator right after any other phase, the message will be treated as an unexpected message and will be sent to the host for action.

The adapter does not support target routines. The adapter will not detect the receipt of an Identify message for a target routine. The host should send a Check Condition status if the initiator attempts to select a target routine.

21020285 D User’s Guide