Avago Technologies LSI53C180 - Manual (Page 14)

1-4 Introduction
In the second example, Figure 1.3 , the LSI53C180 is cascaded to
achieve four distinct SCSI segments. Segments A and D can be treated
as point-to-point segments. Segments B and C are treated as load
segments with at least 8-inch spacing between every node.
Figure 1.3 LSI53C180 SCSI Bus Device
Table 1.2 SCSI Bus Distance Requirements
Segment Mode Length Limit
A LVD (Ultra160) 25 meters
SE (Ultra) 3 meters
1
B LVD (Ultra160) 12 meters
SE (Ultra) 1.5 meters
C LVD (Ultra160) 12 meters
SE (Ultra) 1.5 meters
1. The length may be more, possibly 6 meters, as no devices are
attached to it.
Table 1.3 Transmission Mode Distance Requirements
Segment Mode Length Limit
A, D LVD (Ultra160) 25 meters
SE (Ultra) 1.5 meters
B, C LVD (Ultra160) 12 meters
SE (Ultra) 1.5 meters
Segment A Segment B Segment C
Primary Secondary
Shared Disk
SCSI Bus
Expander SCSI Bus
Expander
Server Server
SCSI Bus
Expander
Segment D
Subsystem
Shared Disk
Subsystem