Figure 3-17. Key Format 4
3.1.3.5
Data Stream Information Fields
For some operations, the data stream will contain a mixture of the IHV, MAC, Key, IV and
AAD information fields. The sequence for these information fields in the source buffer is:
Key, IHV, IV, MAC, and AAD.
Source Buffer 0, Source Buffer 1, Source Buffer 2
Other Source Buffers
Source Data
Key
IHV
IV
MAC
AAD
If a command does not require all fields, those fields may be removed from the data
stream sequence. For example, a “Compression + encryption” command only requires the
Key, IV and AAD information fields.
Source Buffer 0, Source Buffer 1
IV AAD
Other Source Buffers
Source Data
Key
The 820x DMA will extract the information fields from the data stream and send them to
the appropriate engines on the information bus. Please note the actual data stream sent
into the 820x’s data processing channels does NOT include these information fields. When
calculating the “Head Count” and “Source Count” for the command structure, the host
software should exclude the information fields.
820x – Data Sheet, DS-0157-D
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