21020285 D User’s Guide
Chapter 7 Board-control Commands
Page 7 - 6 Start Command List (01H)
Start Command List (01H)With this command you can instruct the RF3880 adapter to begin operating
from a Command List. Since with Command List operation you can attain
higher performance from your SCSI peripheral, this is one of the first
commands you should issue to the adapter. It must be issued by means of a
Single Command Structure.
See Chapter 4, Command Operation for information about using Command
Lists.
Command
Format
The Parameter Block Format for the Start Command List command looks like
this:
Description of
Fields
Each of the fields used by the Start Command List command are expla ined in
the following section:
Command Identifier
The Command Identifier field is used to identify the Status Block associated
with a Parameter Block. It must be a unique value.
Adapter ID
This field must always contain the ID of FFH to indicate a Board-control
command.
Address Modifier
This is the value that the adapter is to drive onto the VMEbus Address Modifier
Lines when selecting the memory address of the Command List.
Command List Memory Address
This field contains the address of the Command List in Memory. It points to
the beginning of the structure: Parameter Block IN index.
Address
Offset Byte Memory Address
Offset + 0 Offset + 1 Offset + 2 Offset + 3
00H Command Identifier
04H Reserved Addr Mod Adapter ID = FFH
08H Command List Memory Address
0CH Reserved Interrupt
10H Command = 01H Reserved
14H Reserved
18H Reserved
Table 60: Start Command List Parameter Block