MCF548x Reference Manual, Rev. 3
22-70 Freescale Semiconductor

Table 22-53 shows the descriptor format to load a previously generated context into the AFEU.

PTR_1 Pointer (not used) NULL
LEN_2 IV Length NULL
PTR_2 IV Pointer NULL
LEN_3 Key Length Number of bytes in key (5–16 bytes)
PTR_3 Key Pointer Address of key to be written into AFEU
LEN_4 Data In Length NULL
PTR_4 Data In Pointer NULL
LEN_5 Data Out Length NULL
PTR_5 Data Out Pointer NULL
LEN_6 IV Out Length NULL
PTR_6 IV Out Pointer NULL
LEN_7 MAC Out Length NULL
PTR_7 MAC Out Pointer NULL
PTR_NEXT Next Descriptor Pointer Pointer to next data packet descriptor

Table 22-53. First Descriptor for a Statically Assigned AFEU Using a Context

Field Name Value/Type Description
Header 0x1500_0050 Don’t permute; context from FIFO (TYPE 0101)
LEN_1 Length (not used) NULL
PTR_1 Pointer (not used) NULL
LEN_2 IV Length Number of bytes in context (259 bytes)
PTR_2 IV Pointer Address of context to be loaded into AFEU
LEN_3 Key Length NULL
PTR_3 Key Pointer NULL
LEN_4 Data In Length NULL
PTR_4 Data In Pointer NULL
LEN_5 Data Out Length NULL
PTR_5 Data Out Pointer NULL
LEN_6 IV Out Length NULL
PTR_6 IV Out Pointer NULL
LEN_7 MAC Out Length NULL

Table 22-52. First Descriptor for a Statically Assigned AFEU Using a Key (Continued)

Field Name Value/Type Description