Emerson MVME147 manual Custom Scsi Packets

Models: MVME147

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CUSTOM SCSI PACKETS

CT words $16 and $18: DATA LENGTH. The number of bytes to transfer during either the data-in or the data-out phase. Not used if DMA is enabled and SG bit is set in status/flag byte in word o.

CT words $1A and $1C: DATA POINTER. If a DATA-IN code is in the TARGET script, the firmware starts transferring data FROM the contiguous data buffer pointed to by this pointer. If a DATA-OUT code is in the TARGET script, the firmware starts transferring data TO the contiguous data buffer pointed to by this pointer. This pointer points to SG table if DMA SG is used.

CT word $1E: MESSAGE-IN LENGTH. Not used by the TARGET role firmware for the message byte count in the message-in phase.

CT words $20 and $22: MESSAGE-IN POINTER. If a message-in code is in the TARGET script, the firmware sends the messages from message-in buffer where this pointer points.

CT word $24: MESSAGE-OUT LENGTH. Not used by the TARGET role firmware.

CT words $26 and $28: MESSAGE-OUT POINTER. If the initiator that is threaded to the MVME147 sends an extended message to the MVME147, the firmware stores it in the message buffer that is pointed to by this pointer. (The ATN condition is only serviced if the ATN signal is asserted during selection or certain phases. The initial IDENTIFY message is handled internally by the firmware for threading purposes. If the ATN condition arises during a phase that can be serviced, the message that is received from the initiator is stored in the buffer pointed to by this message-out pointer.)

CT word $64, even byte : TARGET role firmware SCSI status byte set by firmware during target sequence packet execution..

The remaining bytes of the command table are reserved.

Packet word $0E=$8000:

This word classifies the custom SCSI packet as a TARGET sequence.

Packet word $14=$001C:

This word classifies the packet as a custom SCSI sequence.

Packet word $16:

The interrupt level must be non-zero because TARGET role is only supported for interrupt mode. The vector number provides the return path for the firmware to you.

Packet word $18:

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Emerson MVME147 manual Custom Scsi Packets