Descriptors
MCF548x Reference Manual, Rev. 3
Freescale Semiconductor 22-63

Table 22-44 shows how the length/pointer pairs should be used with the various descriptor types to load

keys, context, and data into the EUs, and how the required outputs should be unloaded.

NOTE

Some of the inputs and outputs will be optional depending on the exact

usage of the descriptor.

0101 common_nonsnoop_afeu Common, nonsnooping, AFEU
0110 hmac_snoop_afeu Snooping, HMAC, AFEU (no context out)
0111 non_hmac_snoop_afeu Snooping, non-HMAC, AFEU
1000 Reserved
1001 Reserved
1010 Reserved
1011 Reserved
1100 hmac_snoop_aesu_ctr AESU CTR hmac snooping
1101 non_hmac_snoop_aesu_ctr AESU CTR non-hmac snooping
1110 hmac_snoop_afeu_ key_in AFEU Context Out Available
1111 hmac_snoop_afeu_ctx_in AFEU Context Out Available

Table 22-44. Descriptor Length/Pointer Mapping

Descriptor
Type L/P 1 L/P 2 L/P 3 L/P 4 L/P 5 L/P 6 L/P 7
0000 Null IV Key Data In Data Out IV Out MAC Out
0001 NULL IV Key Data In Data Out IV Out MAC Out
0010 HMAC Key HMAC Data Key IV Data In Data Out HMAC/Context Out
0011 MD Ctx In IV Key Data In Data Out IV Out MD/Context Out
0100 NULL IV Key Data In Data Out IV Out Key Out via FIFO
0101 NULL IV in via FIFO Key Data In Data Out IV Out via FIFO MD/Context Out
0110 HMAC Key HMAC Data Key IV in via FIFO Data In Data Out HMAC/Context Out
0111 MD Ctx In IV in via FIFO Key Data In Data Out IV Out via FIFO MD/Context Out
1000 —
1001
1010
1011
1100 HMAC Key HMAC Data Key IV Data In Data Out HMAC/Context Out
1101 MD Ctx In IV Key Data In Data Out IV Out MD/Context Out

Table 22-43. Descriptor Types (Continued)

Value Descriptor Type Notes