1 Introducing the DSBE/S SBus Card

The Sun Microsystems Fast Differential SCSI-2/Buffered Ethernet (DSBE/S) SBus card provides a 10 Mbytes/sec differential SCSI-2 interface and a twisted-pair Ethernet channel in a single SBus slot. By combining commonly used functions in a single, low-cost card, the DSBE/S card efficiently utilizes SBus slots.

The DSBE/S SBus card is designed for operation in systems that are running Solaris® 1.1 Rev. A or later - or other compatible operating systems - and is compatible with the OpenBoot(TM) PROM version 2.0 or later. An on-board FCode PROM provides configuration support that identifies the DSBE/S SBus card to the system and contains selftest routines.

The SCSI interface has these features:

• SCSI-2 support

• support of 10-byte commands for Group 2

• bus-initiated selection receives these message bytes:

-1 byte of identify and

-3 bytes of queue tag nexus

• SCSI bus asynchronous data transfers:

• up to 6 Mbytes per second

• SCSI bus synchronous data transfers:

• up to 10 Mbytes per second

• differential SCSI interface

• maximum cable length of 82 feet (25 meters)

• support for up to seven devices

• termination power with PTC protection

The Ethernet interface has these features:

• 128 Kbyte static Ethernet memory

• twisted-pair (10 baseT) Ethernet with RJ45 connector

• 10 Mbit per second transfer rate

• byte, halfword, and 8 halfword DMA bursts to Ethernet memory

• provides operations of up to 100 meters of twisted-pair without the use of a repeater

• detection and correction of wrong polarity on the twisted-pair medium

• jumper-selectable Link Integrity Test feature

The Differential SCSI-2/Buffered Ethernet SBus card is available for all Sun-4C and Sun-4M products.

1.0.1 Setting the J0302 Jumper

Before you install the DSBE/S SBus card, you need to set the J0302 jumper. The J0302 is a two-head jumper that uses a two-pin shunt.

When the shunt is connected across the two ends of the jumper, the 10Base-T Link Integrity Test feature is disabled. When the shunt is removed or left on only one end of the jumper, the jumper is open, and the Link Integrity Test feature is enabled.

The Link Integrity Test feature is a requirement of the IEEE 10Base-T standard that allows the receiver to detect a simplex link failure. The feature can be disabled, however, if a customer has 10BaseT devices that do not support this feature.

The board will be shipped with the Link Integrity Test enabled.

Note - On many 10Base-T hubs, such as the AT&T Starlan(TM), the Link Integrity Test feature can be enabled/disabled by a switch. In such cases, the feature should be enabled on both the hub and DSBE/S. If the customer chooses to disable the feature, it should be disabled both at the hub and the DSBE/S.

To set the J0302 jumper:

1. Remove the DSBE/S SBus card from the antistatic bag.

Spread the bag on a firm surface and use it as a protective mat.

Figure 1-1 Handling the DSBE/S SBus Card

2. Place the SBus card, component side-up, on the bag.

3. Locate the J0302 jumper on the SBus card.

4. Configure the jumper:

a. Use needle-nose pliers and put the shunt over both pins on the jumper to disable the Link Integrity Test feature. Refer to Figure 1-2.

b. Use needle-nose pliers and put the shunt in one pin of the jumper to enable the Link Integrity Test feature. Refer to Figure 1-2.

Figure 1-2 Disabling and Enabling the Link Integrity Test Feature

Figure 1-3 DSBE/S SBus Card Components

Note - In the event of "loss of carrier" or "net responding" problems, check the status of the link enable on the DSBE/S SBus card and on the hub.