LSI 20160 2.2.5 SCSI Bus Termination

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 (seeFigure 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.

Detailed Installation Procedure

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Copyright © 2001 by LSI Logic Corporation. All rights reserved.

Contents

USER’S GUIDE Electromagnetic Compatibility Notices Page Page Preface Related Publications Revision History Contents Appendix A Glossary of Terms and Abbreviations Customer Feedback Figures Page Tables Page Describing the LSI20160 1.1General Description 1.2 Features 1.2.1 PCI Interface 1.2.2 SCSI Interface 1.2.3 Board Characteristics 1.2.4SCSI Activity LED Interface 1.3 Ultra160 SCSI Beneﬁts 1.3.1 Double Transition (DT) Clocking 1.3.2 Cyclic Redundancy Check (CRC) 1.3.3 Asynchronous Information Protection (AIP) 1.4 SureLINK™ Ultra160 SCSI Domain Validation Beneﬁts 1.5 LVDlink™ Technology Beneﬁts 1.6 TolerANT® Technology Beneﬁts Installing the LSI20160 2.1Quick Installation Procedure 2.2 Detailed Installation Procedure 2.2.1 Before You Start 2.2.2 Selecting a PCI Slot 2.2.3 Inserting the Host Adapter Figure 2.2 Inserting the Host Adapter 2.2.4 Connecting SCSI Peripherals 2.2.4.1 Making Internal SCSI Bus Connections Figure 2.4 Internal SCSI Ribbon Cable to Host Adapter Figure 2.5 Internal SCSI Ribbon Cable to Internal SCSI Device Connection Figure 2.6 Connecting Additional Internal SCSI Devices Figure 2.7 Multiple Internal SCSI Devices Chained Together 2.2.4.2 Making Activity LED Connection Figure 2.8 SCSI LED Connector 2.2.4.3 Making External SCSI Bus Connections Figure 2.9 External Cable to Host Adapter Figure 2.10 External Cable to External SCSI Device Figure 2.11 Multiple External SCSI Devices Chained Together 2.2.5 SCSI Bus Termination 2.2.5.1 Internal SCSI Terminations Figure 2.12 Internal SCSI Device Termination 2.2.5.2 External SCSI Terminations Figure 2.13 External SCSI Device Termination 2.2.6 Setting SCSI IDs Table 2.1 SCSI ID Record 2.3 Completing the Installation Technical Speciﬁcations 3.1Physical Environment 3.1.1 Physical Characteristics 3.1.2Electrical Characteristics 3.1.3 Thermal, Atmospheric Characteristics 3.1.4Electromagnetic Compliance 3.1.5 Safety Characteristics 3.2 Operational Environment 3.2.1 The PCI Interface Table 3.2 PCI Connector J1 (Front)1 Table 3.3 PCI Connector J1 (Back)1 3.2.2 The SCSI Interface 3.2.3 The LED Interface 3.3 Subsystem ID and Subsystem Vendor ID Page Appendix A Glossary of Terms and Abbreviations Bus Mastering Byte CISPR Conﬁguration CRC Dword EEPROM EISA External SCSI Device IRQ ISA Kbyte Local Bus Logical Unit NVRAM Operating System Parity Checking Passive PC99 RAM RISC Core ROM SCAM SCSI SCRIPTS Processor SDMS Single-Ended STA SureLINK Ultra160 SCSI VCCI VDE VHDCI Virtual Memory Index Page Customer Feedback Reader’s Comments http://www.lsilogic.com/contacts/na_salesofﬁces.html