Chapter 7 Board-control Commands

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Extended Unit Options (18H)

To receive any number of the first 32 bytes of Request Sense Data (any number over eight will generate multiple Status Blocks for each Request Sense command the adapter issues.):

Place the number desired in the Sense Count field.

Selected Sense Bytes fields are ignored.

Selected Sense Bytes

This part of the Extended Unit Options Parameter Block is a combination of sixteen fields, each containing the byte number of one of 256 possible SCSI Sense bytes. These fields are only valid when the value of the Sense Count field of the Data Structure is zero.

If the Sense Count field contains a 0 and all sixteen fields that make up the Selected Sense Bytes section of the Data Structure are set to 0, the default of eight Sense bytes is returned.

The eight default Sense bytes are displayed as follows:

Byte Memory Address

Offset + 0

Offset + 1

Offset + 2

Offset + 3

 

 

 

 

 

Command Identifier

 

 

 

 

 

Reserved

SCSI Status

Error

Flags

0 = Class/Code

1 = Segment

2 = SCSI Flags

3 = Info Byte

 

 

 

 

4 = Info Byte

5 = Info Byte

6 = Info Byte

7 = Ex Length

Table 107: Default Ordering of Sense Bytes

If the Sense Count field is set to 0, but there are non-zero values in the Selected Sense bytes fields, the byte numbers and order you define in the Selected Sense Bytes fields are used to return automatic Request Sense information for this device.

If you define more than eight bytes to be returned as Sense Data, you will receive two SCSI Pass-through command Status Blocks.

See Chapter 5 for more information about the format of the Status Blocks that will be returned.

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User’s Guide

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Ciprico Rimfire 3880 manual Selected Sense Bytes