Freescale Semiconductor MCF5480 User Manual
Page 678

MCF548x Reference Manual, Rev. 3
22-76
Freescale Semiconductor
shows the final descriptor that performs a cipher on data using the key and optional context
(IV) that were loaded into the DEU by a previous descriptor, then optionally unloads the context.
lists the specific descriptors that use the format shown in
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 22-63. Final Descriptor for a Statically Assigned DEU
Field Name
Value/Type
Description
Header
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
Number of bytes of output IV to be written (always 8)
(optional)
PTR_6
IV Out Pointer
Address where output IV is to be written (optional)
LEN_7
MAC Out Length
NULL
PTR_7
MAC Out Pointer
NULL
PTR_NEXT
Next Descriptor Pointer Pointer to next data packet descriptor
Table 22-64. Typical Header Values Final 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 22-62. Typical Header Values for Middle Static DEU Descriptor Format (Continued)
Header Value
E/C
S/T
E/D