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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:
Bit
7
Byte
0
1
2
3
4
5
6
7
Code
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-5 drive SDX-1100V series Ver.1.0
PARALLEL PROTOCOL REQUEST
6
5
4
EXTENDED MESSAGE (01h)
EXTENDED MESSAGE LENGTH (06h)
PARALLEL PROTOCOL REQUEST (04h)
TRANSFER PERIOD FACTOR
REQ/ACK OFFSET
TRANSFER WIDTH EXPONENT (m)
RESERVED
TRANSFER PERIOD FACTOR FIELD
3
2
RESERVED
QAS_REQ
Description
5.SCSI Interface
1
0
DT_REQ
IU_REQ
5-5
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