Freescale Semiconductor MCF5480 - Manual (Page 683)

EU Specific Data Packet Descriptors
MCF548x Reference Manual, Rev. 3
Freescale Semiconductor 22-81
Table 22-72 lists several different descriptors that use the middle descriptor format shown in Table 22-71 .
NOTE
For the middle descriptor the HMAC bit should always be cleared, even if
HMAC is the desired final value. Therefor the table below does not include
any HMAC specific settings.
Table 22-73 shows the final descriptor for a statically assigned MDEU.
LEN_2 IV Length Number of bytes in intermediate hash input (16, 20, or 32 bytes)
PTR_2 IV Pointer Pointer to location of intermediate hash input
LEN_3 Key Length Number of bytes of key (only used for HMAC mode)
PTR_3 Key Pointer Pointer to key (only used for HMAC mode)
LEN_4 Data In Length Number of bytes of data to be hashed (64 bytes)
PTR_4 Data In Pointer Pointer to data to perform hash upon
LEN_5 Data Out Length NULL
PTR_5 Data Out Pointer NULL
LEN_6 IV Out Length Number of bytes in intermediate hash output (16, 20, or 32 bytes)
PTR_6 IV Out Pointer Pointer to location where intermediate hash output is to be written
LEN_7 MAC Out Length NULL
PTR_7 MAC Out Pointer NULL
PTR_NEXT Next Descriptor Pointer Pointer to next data packet descriptor
Table 22-72. Typical Header Values for Using Middle Static MDEU Descriptor Format
Header Value Algorithm HMAC Pad
0x38100010 SHA256 No No
0x38200010 MD5 No No
0x38000010 SHA No No
Table 22-73. Final Descriptor for a Statically Assigned MDEU
Field Name Value/Type Description
Header see Table 22-74 Header common to several descriptors (TYPE 0001)
LEN_1 Length (not used) NULL
PTR_1 Pointer (not used) NULL
LEN_2 IV Length Number of bytes in intermediate hash (16, 20, or 32 bytes)
PTR_2 IV Pointer Pointer to location of intermediate hash
LEN_3 Key Length Number of bytes of key (only used for HMAC mode)
Table 22-71. Middle Descriptor for a Statically Assigned MDEU (Continued)
Field Name Value/Type Description