Descriptor Format: Pointer Dwords - Freescale Semiconductor MPC8313E Family Reference Manual

Value
(Binary)
1010_1
Others
1
Type 0000_0 is for AES-CTR operations. Type 0001_0 also supports AES-CTR, however, to use AES-CTR with 0001_0, the
user must pre-pend zeros to the AES-Ctx before loading the AES context registers.
2
Type 1100_0 is for AES-CTR operations with HMAC. Type 0010_0 also supports AES-CTR with HMAC, however, to use
AES-CTR with 0010_0, the user must pre-pend zeros to the AES-Ctx before loading the AES context registers.
For more about descriptor types and the data used for each type, see
14.3.3

Descriptor Format: Pointer Dwords

The descriptor contains seven 'pointer dwords,' which define where in memory the SEC should access its
input and output data parcels. The pointer dwords are numbered 0–6 as shown in
determines how it will use each of the pointer dwords based on the 'Descriptor Type' and 'Direction' fields
in the header. The channel accesses the first data parcel by starting at a location given by a POINTER
value, and accessing a number of bytes given by a LENGTH or EXTENT value. Subsequent data parcels
may be accessed by starting where a previous data parcel ended, or by starting at a different POINTER.
The LENGTH or EXTENT used with any POINTER may be from the same pointer dword or from a
different pointer dword in the same descriptor. Although the EXTENT field exists in each pointer dword
of the SEC descriptor, only the EXTENTs in pointer dwords 3, 4, and 5 are currently in use.
Bit # 0
LENGTH
Bits Name
0–15 LENGTH Length. A number of bytes in the range 0–65535. The use of this field depends on the 'Descriptor
Type' and 'Direction' in the header dword. A value of zero causes the channel to skip this dword.
16 J Jump. Determines whether to 'jump' to a link table whenever the POINTER field in this same lword is
used.
0 The POINTER field points to data.
1 The POINTER field points to a link table, and scatter/gather is enabled.
17–23 EXTENT Extent. A number of bytes in the range 0–127. The use of this field depends on the 'Descriptor Type'
and 'Direction' in the header dword.
24–31 — Reserved
32–63 POINTER Pointer: A memory address.
On occasion, a descriptor field may not be applicable to the requested service. With seven pointer dwords,
it is possible that not all these dwords will be required to specify the input and output parameters. (Some
MPC8313E PowerQUICC II Pro Integrated Processor Family Reference Manual, Rev. 3
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Table 14-7. Descriptor Types (continued)
Descriptor Type
raid_xor XOR 3 sources together
— Reserved
15 16 17
J EXTENT
Figure 14-5. Pointer Dword
Table 14-8. Pointer Dword Field Definitions
Notes
Section 14.3.5, "Descriptor Types."
23 24 31 32
—
Description
Security Engine (SEC) 2.2
Figure 14-3. The channel
63
POINTER
14-15