
6
TARGET ROLE ROUTINES
particular device on the SCSI bus. The indexing is accomplished by simply splitting the 64 entries into 8 entries of 8 peripheral devices. Each block of eight devices corresponded to each SCSI device. The MVME147 is one of these SCSI devices. Seven other SCSI devices may be added to the SCSI bus to perform some application. As long as there is another SCSI device that can play the initiator role on the bus, then the MVME147 may also play the TARGET role on the bus. The eight entries under the SCSI device entry deal with TARGET support of eight peripheral devices. In other words, the SCSI firmware TARGET role routines allow support of eight peripheral devices associated with the MVME147.
The method of addressing these peripheral devices is through the concept of logical units. Because the MVME147 supports eight logical units on the SCSI bus, LUN 0 may be a printer, LUN 1 may be an
SCSI Versus SASI Rules
As far as the SCSI firmware is concerned, a SCSI system is one that supports arbitration, reselection, and the
MVME147 SCSI Firmware TARGET Role Structure Requirements
The following sections describe the data structures required by the SCSI firmware for the TARGET role custom sequence packets. Refer to Chapter 2.
Custom Sequence Packet
Custom Sequence packets are detailed in Chapter 2.