3 descriptor type formats, Descriptor type formats -62, Figure 22-45 – Freescale Semiconductor MCF5480 User Manual

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MCF548x Reference Manual, Rev. 3

22-62

Freescale Semiconductor

Figure 22-45. Chain of Descriptors

22.13.3 Descriptor Type Formats

The SEC accepts 12 fixed format descriptors. The descriptor TYPE field in the descriptor header informs

the crypto-channel of the ordering of the inputs and outputs defined by the length/pointer pairs in the

descriptor body. The ordering of inputs and outputs in the length/pointer pairs (as defined by descriptor

type) are shown in

Table 22-44

Table 22-43

shows the permissible values for the TYPE field in the descriptor header.

NOTE

Not all descriptor types are operationally useful. Some exist for test and

debug reasons and to provide flexibility in dealing with evolving security

standards. The cryptographic transforms required by most security

protocols use types 0001 and 0010.

Table 22-43. Descriptor Types

Value

Descriptor Type

Notes

0000

aesu_ctr_nonsnoop

AESU CTR nonsnoooping

0001

common_nonsnoop_no_afeu

Common, nonsnooping, non-PKEU, non-AFEU

0010

hmac_snoop_no_afeu

Snooping, HMAC, non-AFEU

0011

non_hmac_snoop_no_afeu

Snooping, non-HMAC, non-AFEU

0100

aseu_key expand_output

Non-snooping, non HMAC, AESU, expanded key out

DPD–DES–CTX_CRYPT
LEN_CTXIN
PTR_CTXIN
LEN_KEY
PTR_KEY
LEN_DATAIN
PTR_DATAIN
LEN_DATAOUT
PTR_DATAOUT
LEN_CTXOUT
PTR_CTXOUT
null length
null pointer
null length
null pointer
PTR_NEXT

This manual is related to the following products:

MCF5485 MCF5483 MCF5484 MCF5482 MCF5481