Avago Technologies LSI53C320 - Manual (Page 13)

Applications 1-3
Version 2.2 Copyright © 2003 by LSI Logic Corporation. All rights reserved.
1.2 Applications
The LSI53C320 supports
•
server clustering environments
•
expanders creating distinct SCSI cable segments that are isolated
from each other
Configurations that use the LSI53C320 SCSI Bus Expander in the LVD
to LVD mode allow the system designer to take advantage of the inherent
cable distance, device connectivity, data reliability, and increased transfer
rate benefits of LVD signaling with Ultra320 SCSI peripherals.
Section
2.2.3, “Maximum Cable Lengths,” discusses additional limits on the total
SCSI cable length for systems operating at Ultra320 SCSI transfer rates.
Figure 1.2 shows how SCSI bus expanders couple bus segments with no
impact on the SCSI protocol or software. Two LSI53C320 expanders
configure three bus segments. Segment A is a point-to-point segment.
Segments B and C are load segments and have at least 8 inches
between every node.
Table 1.2 shows the various distance requirements
for each SCSI bus segment.
Figure 1.2 LSI53C320 Server Clustering
Segment A Segment B
Segment C
Primary Server Secondary Server
Shared Disk Subsystem
SCSI Bus
Expander
SCSI Bus
Expander