21020285 D User’s Guide
Chapter 7 Board-control Commands
Page 7 - 18 Unit Options (08H)
Unit Options (08H)
The Unit Options command allows you to individually tailor how the RF3880
adapter operates, in either initiator or target mode, with each SCSI device on
the bus.
Usually these options need be set only once, at power-up, to create the proper
operating environment. Each unit you need to set-up requires a separate Unit
Options command.
Command
Format
The Parameter Block for the Unit Options command looks like this:
Description of
Fields
Each of the fields of the Parameter Block are described below:
Command Identifier
This field is used if you are issuing the Unit Options command through the
structure of a Command List. It is used to identify the Status block returned
from the command. It should be a unique value.
Adapter ID
This command performs no action on a specific SCSI device. It is a Board-
control command and so this field must be FFH.
Unit SCSI ID
This field must contain a number from 0 - FH representing a SCSI device on
the bus. Do not use the RF3880 adapter SCSI ID you assign with the General
Options command.
Address
Offset Byte Memory Address
Offset + 0 Offset + 1 Offset + 2 Offset + 3
00H Command Identifier
04H Disconnect Time-out Unit SCSI ID Adapter ID = FFH
08H Select Time-out Retry Control Retry Limit
0CH Reserved Reserved Sense Count Unit Flags
10H Command = 08H Reserved
14H Sense Byte # Sense Byte # Sense Byte # Sense Byte #
18H Sense Byte # Sense Byte # Sense Byte # Sense Byte #
Table 74: Unit Options Command Parameter Block