Fujitsu MBA3073 SERIES Technical Manual page 147

The SCAM target enters the Power-On Delay status immediately after the power-on, and allows the
local initialization to start. The SCAM target shall exit this status, and enter the Initial SCAM Protocol
status within a SCAM power-on to SCAM selection delay.
During Initial SCAM Protocol status, the level-2 SCAM target arbitrates the SCSI bus without using
the ID and performs the SCAM selection. After SCAM selection delay, the SCAM target checks the
SCSI bus and determines the C/D signal status. If the C/D signal is true, the SCAM initiator exists and
its SCAM target enters in the ID Assignable status. If the C/D signal is false, the SCAM initiator does
not exist and its SCAM target enters the SCAM Monitor status. Note that the level-2 SCAM target
starts the SCAM protocol only once after the power-on.
During SCAM Monitor status, the SCAM target shall monitor the SCSI bus for both SCAM selection
and normal SCSI selection. When the SCAM target detects the start of SCAM protocol, it shall enter
the ID Assignable status. If the SELECTION phase of the current IDs of SCAM target continues to
valid during at least the response delay of SCAM unassigned ID selection, this SCAM target shall
respond to the selection and assert the BSY signal. The SCAM target shall implicitly enter the ID
Assigned status as if its ID assignment was explicitly accepted. The assigned ID is set as the current
ID, and the SCAM target functions as the SCAM tolerant device.
The SCAM target continues in the ID Assignable status as long as the SCAM protocol is
controlled. It continues until the status is changed by the SCAM function. When the SCAM
target is separated and its Assign ID action code is received, the specified ID is set to the current
and already assigned ID. The SCAM target releases all SCSI bus signals, and enters the Assigned
ID status. When the SCAM target receives a Configuration Process Complete function code or
the SCAM protocol has ended (if the C/D signal becomes false), the target shall release all SCSI
bus signals and enter the ID Unassigned status.
Note:
The SCAM target may not recognize the Configuration Process Complete function code at the
end of SCAM protocol, and may return to the SCAM Monitor status.
The SCAM target in the ID Unassigned status is the one to which no SCSI ID has been assigned
both explicitly and implicitly. It does not respond to the SCSI selection of the current ID
regardless of the period. The SCAM target can exit from the ID Unassigned status only when it
has detected the start of SCAM protocol, except for the power-on or reset status.
Once the SCAM target has entered the ID Assigned status, it functions as an SCAM tolerant device
with the already assigned ID. That is, it responds to the SCSI selection within the response time of
SCAM tolerant selection but does not respond or recognize the SCAM selection.
The SCAM target can enter the Reset Delay status and allow local initialization by the reset status.
The SCAM target exists this status and enters the SCAM Monitor status within the period between
SCAM reset and SCAM selection.
(4) Interconnection of various width buses
If an SCSI-3 device is mixed with an SCSI-1 or SCSI-2 device, a problem may occur. The SCSI-
3 TERMPWR requirements have been expanded to support the 16-bit data bus. During this time,
the SCSI-1 and SCSI-2 devices cannot supply enough TERMPWR. Also, an additional
TERMPWR source (such as an SCSI-3 device) may be required.
1-67 C141-C007