21020285 D User’s Guide
Chapter 5 Initiator Mode Pass-through Commands
Page 5 - 12 Initiator Pass-through Status Block Format
Initiator Pass-through Status Block Format
In Chapter 4, a Base Status Block was introduced and explained in general
terms. The Status Block for an Initiator Pass-through command encompasses
the same fields used for the Board-control commands, plus i t holds information
that is particular to a SCSI transaction: a SCSI status byte, and eight bytes of
Sense data returned from the SCSI device.
The Sense Data fields are an important part of the Status Block. Sense data is
acquired directly from the SCSI device; you can enable the adapter to
automatically request Sense Data in response to an error condition reported
from the device. What you will see in these fields is affected by your use of the
Unit Options or Extended Unit Options Board-control commands. If you use
one of these commands to have more than eight bytes of Sense Data returned,
you will receive multiple Status Blocks.
This section includes information about all the fields you will see when
examining a Status Block returned from a Initiator Pass-through command.
Status Block
Format
This is the format you can expect from an Initiator Pass-through Status Block:
Note
The fields displayed in
08H and 0CH are the
default Sense Bytes
returned by Initiator
Pass-through
Description of
Fields
Following is a brief description of each of the fields:
Command Identifier
This value links a Status Block with a Parameter Block.
Flags
This byte can be polled to ascertain whether, and i n what condition, a command
completed:
TMS Target Mode Status - This bit is will not be true for an Initiator Pass-
through command status block.
Address
Offset Byte Memory Address
Offset + 0 Offset + 1 Offset + 2 Offset + 3
00H Command Identifier
04H Reserved SCSI Status Error Flags
08H 0 = Class/Code 1 = Segment 2 = SCSI Flags 3 = Info Bytes
0CH 4 = Info Byte 5 = Info Bytes 6 = Info Byte 7 = Ex Length
Table 34: SCSI Pass-through Status Block
BITS
76543210
CC ERR RTY DTT DTG CSB 0 TMS = 0
Table 35: Bit-meanings of Flags Field