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User’s Guide 21020285 D
Chapter 5 Initiator Mode Pass-through Commands
Initiator Pass-through Parameter Block Format Page 5 - 3
Initiator Pass-
through
Parameter
Block Format
In Chapter 4, a Base Parameter Block was introduced and explained in a general
context. Parameter Blocks are the same size, with the same general fields,
whether you are issuing a Pass-through command or an adapter Board-control
command. The information specific to Initiator Pass-through commands will
be covered in this section.
Command
Format
Use this format when issuing a Parameter Block containing an Initiator Pass-
through command:
Description of
the Fields
The Initiator Pass-through commands Parameter Block fields can be explained
as follows:
Command Identifier
The Command Identifier field is used to identify the Status Block associated
with a Parameter Block.
It must be a unique value.
Target ID
This value identifies the Target ID of the device that is to receive the command
contained in the SCSI Command Descriptor Block.
Address Modifier
This value further defines the VMEbus Address specified for a data transfer.
Note
Valid Address Modifier
values can be found by
referring to a VME
Specification, Revision
D.
Addr Mod Address Modifier - These six bits inform the RF3880 adapter
what Address Modifier it should use for data transfer.
Address
Offset
Byte Memory Address
Offset + 0 Offset + 1 Offset + 2 Offset + 3
00H Command Identifier
04H Flags-2 Flags-1 Addr. Mod. Target ID
08H VME Memory Address
0CH Transfer Count
10H 0 (OP Code) 1 2 3 SCSI 6, 10 or
12 byte
Command
Descriptor
Block
14H4567
18H 8 9 10 11
Table 25: Initiator Pass-through Parameter Block
BITS
76543210
00 Addr Mod
Table 26: Bit-meanings of Address Modifier Field