Intel SPSH4 - Server Platform - 0 MB RAM, Technical Product Specification

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SCSI Bay Boardset SPSH4 Server System External Product Specification
Revision 1.11 54
6.3.3 SCSI Multi-ModeTermination
The multi-mode terminators provide SCSI-4 compliant termination for the backplane. These
terminators provide termination in both SE modes and LVD mode.
6.3.4 SCSI Interface
The SCSI interface on the LVD/SE SCSI backplane provides the link between the SCSI bus and
the microcontroller (containing the intelligence for the LVD/SE SCSI backplane). This interface
allows the microcontroller to respond as a SCSI target to implement the SAF-TE protocol. This
is implemented using a Symbios Logic* 53C80S SCSI interface chip (or equivalent).
6.3.5 Power Control
Power control on the LVD/SE SCSI backplane supports the following features. Without the
population of the SAF-TE card, power to the drives is always on.
•
Spin-down of a drive when failure is detected and reported (using enclosure services
messages) via the SCSI bus. An application or RAID controller detects a drive-related
problem that indicates a data risk. In response, it removes the drive from service and
sends a spin-down SCSI command to the drive. This decreases the likelihood that the
drive will be damaged during removal from the hot-swap drive bay. When a new drive is
inserted, the power control waits a short amount of time for the drive to be fully seated
before it applies power with a controlled power ramp.
•
If the system power is on, the LVD/SE SCSI backplane immediately powers off a drive
slot when it detects that a drive has been removed. This prevents possible damage to
the drive when it is partially removed and re-inserted while full power is available, and
disruption of the entire SCSI array from possible sags in supply voltage and resultant
current spikes.
6.3.6 FET Short Protection
The FET short protection circuit is useful to protect both 12 volt and 5 volt power control FETs
located on LVD/SE SCSI backplane.