Freescale Semiconductor MCF5480 - Manual (Page 682)

MCF548x Reference Manual, Rev. 3
22-80 Freescale Semiconductor
Table 22-70 lists several different descriptors that use the format shown in Table 22-69 .
Table 22-71 shows the middle descriptor for a statically assigned MDEU.
Table 22-69. First Descriptor for a Statically Assigned MDEU
Field Name Value/Type Description
Header see Table 22-70 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 of IV to be written (optional) (40 bytes)
PTR_2 IV Pointer Pointer to context to be written into MDEU (optional)
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 22-70. Typical Header Values for Using First Static MDEU Descriptor Format
Header Value Algorithm HMAC Pad
0x31100010 SHA256 No No
0x31200010 MD5 No No
0x31000010 SHA No No
0x39900010 SHA256 Yes No
0x39A00010 MD5 Yes No
0x39800010 SHA Yes No
Table 22-71. Middle Descriptor for a Statically Assigned MDEU
Field Name Value/Type Description
Header see Table 22-72 Header common to several descriptors (TYPE 0001)
LEN_1 Length (not used) NULL
PTR_1 Pointer (not used) NULL