SCSI CDB
In SCSI computer storage, commands are sent in a Command Descriptor Block (CDB).
Each CDB can be a total of 6, 10, 12, or 16 bytes, but later versions of the SCSI standard also allow for variable-length CDBs. The CDB consists of a one byte operation code followed by some command-specific parameters.
A typical CDB structure is:
bit→ |
7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
|---|---|---|---|---|---|---|---|---|
0 |
Operation code = 03h |
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1 |
LUN |
Reserved |
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2 |
Reserved |
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3 |
Reserved |
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4 |
Allocation length |
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5 |
Control |
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