Sony SDX-800V manual Command Complete 00h, Extended Message 01h, Parallel Protocol Request 04h

5.SCSI Interface

5.3.1.COMMAND COMPLETE (00h)

This message is sent from a target to an initiator to indicate that the execution of a command or a series of linked commands has completed and valid status has been sent to the initiator. After successfully sending this message, the target goes to the BUS FREE phase by releasing BSY.

When received as a target, it will be handled as an illegal message, the unit will return MESSAGE REJECT and will enter the status phase reporting CHECK CONDITION with the sense key set to COMMAND ABORTED.

5.3.2.EXTENDED MESSAGE (01h)

5.3.2.1.PARALLEL PROTOCOL REQUEST (04h)

PARALLEL PROTOCOL REQUEST messages are used to negotiate a synchronous data transfer agreement, a wide data transfer agreement, and set the protocol options between two SCSI devices. Negotiations using this message shall only be initiated by initiators. A Parallel Protocol Request message has the following format:

PARALLEL PROTOCOL REQUEST

Bit	7	6	5		4		3	2		1	0
Byte
0					EXTENDED MESSAGE (01h)
1			EXTENDED MESSAGE LENGTH (06h)
2			PARALLEL PROTOCOL REQUEST (04h)
3				TRANSFER PERIOD FACTOR
4						RESERVED
5						REQ/ACK OFFSET
6			TRANSFER WIDTH EXPONENT (m)
7			RESERVED						QAS_REQ	DT_REQ	IU_REQ

	TRANSFER PERIOD FACTOR FIELD
Code	Description
	Transfer period equals 12.5 ns (Fast-80 data is latched every 12.5 ns). This code is only
09h	valid if the protocol options field has a value selected that supports double transition data
	transfer (DT_REQ is one)
0Ah	Transfer period equals 25 ns (Fast-40 data is latched every 25 ns or 30.3 ns).
0Bh	Transfer period equals 30.3 ns (Fast-40 data is latched every 25 ns or 30.3 ns).
0Ch	Transfer period equals 50 ns (Fast-20).
0Dh-18h	Transfer period equals the period factor x 4 (Fast-20).
19h-31h	Transfer period equals the period factor x 4 (Fast-10).
32h-FFh	Transfer period equals the period factor x 4

For single transition (ST) synchronous data transfer the REQ/ACK OFFSET is the maximum number of REQ assertions allowed to be outstanding before a corresponding ACK assertion is received at the target. The size of a data transfer may be 1 or 2 bytes depending on the values in the transfer width exponent field.

For double transition (DT) synchronous data transfer the REQ/ACK OFFSET is the maximum number of REQ transitions allowed to be outstanding before a corresponding ACK transition is received at the target. The size of a data transfer shall be 2 bytes.

SONY AIT-3Ex drive SDX-800V series Ver.1.1 5-5