LSI 20160 - Manual (Page 33)

Detailed Installation Procedure 2-15
Copyright © 2001 by LSI Logic Corporation. All rights reserved.
2.2.5 SCSI Bus Termination
The devices making up the SCSI bus are connected serially (chained
together) with SCSI cables. The first and last physical SCSI devices
connected on the ends of the SCSI bus must have their terminators
active. All other SCSI devices on the bus must have their terminators
removed or disabled.
Termination control has two options which allow a different termination
mode:
•
Termination can be disabled by placing a manual shunt over the
post. When the shunt is off, the terminator is active. When the shunt
is on the post, the terminator is disabled.
•
Termination can be enabled or disabled for a specific channel using
software control with GPIO3.
LVD peripheral devices are normally terminated with external
terminators, but are sometimes set with jumpers or with a switch on the
peripheral. Refer to the peripheral manufacturer’s instructions and to the
user’s manual for your computer for information on how to identify the
terminator setting of each device and how to change it.
The LSI20160 automatically controls SCSI bus termination for two
different bus configurations (see
Figure 2.1 ). The two bus configurations
are
•
Termination on
•
Termination off
You can disable termination in two ways:
•
Use BIOS software control, where the BIOS termination option is
changed from Automatic to Off.
•
Manually place a shunt on the post of the respective jumpers, J2DIS
and J4DIS.