Emerson MVME147 manual TARGET Sequence Custom Packet

Models: MVME147

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TARGET Sequence Custom Packet

D7 = Not used by the TARGET role firmware. (This is the link bit. Command linking is not accomplished with the use of this bit.)

D6 = Not used by the TARGET role firmware. (This is the parity bit. )

D5 = Not used by the TARGET role firmware. (This is the DMA disables bit. DMA is used in TARGET role: 0 = DMA, 1 = no DMA)

D4 = MUST be zero. Not used by the TARGET role firmware. (This is the interpret bit and only relevant for initiator role.)

D3 = Not used by the TARGET role firmware. (This is the SASI/SCSI rule bit. The TARGET role module determines which rule to follow by the initiator assertion of ATN and the re-select option bit of the IDENTIFY message.)

D2 = This is a scatter/gather bit. If DMA is enabled, the data pointer in the command table could be used to point to the scatter/gather table if this bit is 1.

D1 = 1 = SYNC transfer enable.

0 =ASYNC transfer enable.

D0 = Reserved.

(Byte 01): Not used by the TARGET role firmware. Must be set to $00.

CT words $02 and $04: LINK POINTER. Not used by the TARGET role firmware.

CT word $06: COMMAND LENGTH. Not used by the TARGET sequence call. (The CDB received from initiator is stored in the command table that was provided in the TARGET enable call. You may use the same command tables for the enable and sequence calls to interpret receive CDB, but the TARGET sequence call does not make use of the command length and of the CDB itself.)

CT words $08 through $12: COMMAND DESCRIPTOR BLOCK. Not used by the TARGET sequence call. (Refer to CT word 06 above for command length.)

CT word $14, even byte: User SCSI STATUS. For a TARGET sequence, you can set the vendor unique bits in the status byte. The MVME147 SCSI firmware sends the contents of this byte ORed with the firmware SCSI status byte in offset $64 if a status phase code is encountered in the TARGET script. (Odd byte $15: initiator SCSI address which is interfacing with the TARGET role firmware.)

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Page 37
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Emerson MVME147 manual TARGET Sequence Custom Packet