MSC8144E Reference Manual, Rev. 3
26-38
Freescale
Semiconductor
Security Engine (SEC)
26.4.1.11.24 SPK_BUILD: Build PK Data Structure (0xFF)
This routine must always precede any of eight elliptic curve routines, in order to prepare the data
structure required by those routines.
Input: A0, A1, A2, A3, B0, B1 = parameters required by the elliptic curve routines
Output: PK_BUILD = B1
•
B0
•
A3
•
A2
•
A1
•
A0, a structure of 1536 bits (384 bytes),
(where
•
represents a concatenation of memory segments) In PK_BUILD, each segment is
right-justified and zero-padded on the left to a total of 512 bits
Requirements: maximum size of each parameter = 511 bits
26.4.2 Data Encryption Standard Execution Unit (DEU)
In typical operation, the DEU is used through channel-controlled access, which means that most
reads and writes of DEU registers are directed by the SEC channels. Driver software performs
core processor-controlled register accesses only on a few registers for initial configuration and
error handling.
The following subsections include general descriptions of the DEU registers and structures.
Section 26.5, Programming Model, on page 26-66 provides a detailed description of each
register and associated register fields.
26.4.2.1 DEU Mode Register
The DEU Mode Register contains 3 bits used to program DEU operation. The Mode Register is
cleared when the DEU is reset or reinitialized. Setting a reserved mode bit generates a data error.
If the Mode Register is modified during processing, a context error is generated.
26.4.2.2 DEU Key Size Register
The key size value indicates the number of bytes of key memory to use in encrypting or
decrypting. If the DEU Mode Register is set for single DES, any value other than 8 bytes
automatically generates a key size error in the DEU Interrupt Status Register. If the mode bit is
set for triple DES, any value other than 16 bytes (112 bits for 2-key triple DES (K1 = K3)) or 24
bytes (168 bits for 3-key triple DES) generates an error. Triple DES always uses K1 to encrypt,
K2 to decrypt, K3 to encrypt.
26.4.2.3 DEU Data Size Register
This register stores the number of bits in the final message and has an upper bound of 4096.
Whatever number is written (and whatever truncated value is stored) must be a multiple of 64.
All data processed by the DEU must be a multiple of the DES algorithm block size of 64 bits; the
DEU does not automatically pad messages out to 64-bit blocks. If a data size that is not a multiple
of 64 bits is written, a data size error is generated. Only bits 7–0 are checked to determine if there
Summary of Contents for MSC8144E
Page 1: ...MSC8144E Reference Manual Quad Core Media Signal Processor MSC8144ERM Rev 3 July 2009 ...
Page 48: ...MSC8144E Reference Manual Rev 3 xlviii Freescale Semiconductor ...
Page 86: ...MSC8144E Reference Manual Rev 3 1 38 Freescale Semiconductor Overview ...
Page 168: ...MSC8144E Reference Manual Rev 3 3 60 Freescale Semiconductor External Signals ...
Page 242: ...MSC8144E Reference Manual Rev 3 5 26 Freescale Semiconductor Reset ...
Page 314: ...MSC8144E Reference Manual Rev 3 8 24 Freescale Semiconductor General Configuration Registers ...
Page 414: ...MSC8144E Reference Manual Rev 3 10 14 Freescale Semiconductor MSC8144E SC3400 DSP Subsystem ...
Page 452: ...MSC8144E Reference Manual Rev 3 11 38 Freescale Semiconductor Internal Memory Subsystem ...
Page 520: ...MSC8144E Reference Manual Rev 3 12 68 Freescale Semiconductor DDR SDRAM Memory Controller ...
Page 1070: ...MSC8144E Reference Manual Rev 3 21 28 Freescale Semiconductor Timers ...