EU Specific Data Packet Descriptors
MCF548x Reference Manual, Rev. 3
Freescale Semiconductor 22-75

Table 22-61 shows the middle descriptor that performs a cipher on data using the key and optional context

(IV) that were loaded into the DEU by the first descriptor.

Table 22-62 lists the specific descriptors that use the format shown in Table 22-61.

0x20700010 CBC Triple DES Encrypt
0x20600010 CBC Triple DES Decrypt
0x20100010 ECB Single DES Encrypt
0x20000010 ECB Single DES Decrypt
0x20300010 ECB Triple DES Encrypt
0x20200010 ECB Triple DES Decrypt

Table 22-61. Middle Descriptor for a Statically Assigned DEU

Field Name Value/Type Description
Header Table 22-62 Header common to several descriptors (TYPE 0001)
LEN_1 Length (not used) NULL
PTR_1 Pointer (not used) NULL
LEN_2 IV Length NULL
PTR_2 IV Pointer NULL
LEN_3 Key Length NULL
PTR_3 Key Pointer NULL
LEN_4 Data In Length Number of bytes of data to be ciphered (multiple of 8)
PTR_4 Data In Pointer Address of data to be ciphered
LEN_5 Data Out Length Bytes of output data (should be equal to length of data in)
PTR_5 Data Out Pointer Address to write output data
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 22-62. Typical Header Values for Middle Static DEU Descriptor Format

Header Value E/C S/T E/D
0x20500010 CBC Single DES Encrypt
0x20400010 CBC Single DES Decrypt
0x20700010 CBC Triple DES Encrypt

Table 22-60. Typical Header Values for First Static DEU Descriptor Format (Continued)

Header Value E/C S/T E/D