MSC8144E Reference Manual, Rev. 3
26-160
Freescale
Semiconductor
Security Engine (SEC)
AFEUMR[CS] bit (see Section 26.4.5.1, AFEU Mode Register, on page 26-54). See Section
26.5.10.12, AFEU FIFOs, on page 26-160 for details about AFEU FIFO addressing.
Note:
The AFEU Context Memory is in the range defined by offsets 0xC8100–0xC81FF.
26.5.10.10 AFEU Context Memory Pointer Register (AFEUCMPR)
The context memory pointer register holds the internal context pointers that are updated with
each byte of message processed. These pointers correspond to the values of I, J, and Sbox[I+1] in
the ARC-4 algorithm. If this register is written during message processing, a context error will be
generated. When performing ARC-4 operations, the user has the option of performing a new
S-Box permutation per packet, or unloading the contents of the S-box (context) and reloading this
context prior to processing of the next packet. The S-Box contents (256 bytes) plus the three
bytes of the context memory pointers are unloaded and reloaded via the AFEU FIFOs. AFEU
Context consists of the contents of the S-Box, as well as three counter values, which indicate the
next values to be used from the S-Box. Context must be loaded in the same order in which it was
unloaded.
Note:
The AFEUCMPR is located at offset 0xC8200.
26.5.10.11 AFEU Key Registers (AFEUKR[1–2])
AFEU uses two write-only key registers to guide initial permutation of the AFEU S-Box, in
conjunction with the AFEU Key Size Register. AFEU performs permutation starting with the
first byte of key register 0, and uses as many bytes from the two key registers as necessary to
complete the permutation. Reading either of these memory locations generates an address error
interrupt.
Note:
The AFEU key registers are located at the following offsets:
AESUKR1 = Offset 0xC8400.
AESUKR2 = Offset 0xC8408.
26.5.10.12 AFEU FIFOs
AFEU uses an input FIFO/output FIFO pair to hold data before and after the encryption process.
Normally, the channels control all access to these FIFOs. For core processor-controlled
operation, a write to anywhere in the AFEU FIFO address space enqueues data to the AFEU
input FIFO, and a read from anywhere in the AFEU FIFO address space dequeues data from the
AFEU output FIFO.
Note:
The AFEU FIFOs reside in the range defined by offsets 0xC8800–0xC8FFF. In the
special case where context is written through the input FIFO, the first write must be to
address offset 0xC8E00. Context reads can be from any address in the FIFO address
range.
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 ...