Arc Four Execution Unit; Arc Four Execution Unit Registers - Motorola DigitalDNA MPC180E User Manual

Chapter 5

Arc Four Execution Unit

This chapter explains how to program the AFEU (Arc Four Execution Unit) to encrypt or
decrypt a message.

5.1 Arc Four Execution Unit Registers

All operational registers within the main control block are 32-bit addressable. However,
they may contain less than 32 bits.
Table 5-1 lists AFEU registers. These registers are described in more detail in the following
sections.
Table 5-1. Arc Four Execution Unit (AFEU) Registers
MPC180E 12-Bit Address
0x400
0x401
0x402
0x403
0x404
0x405
0x406
0x407
0x408
0x409
0x40A
0x40B
0x410
0x414
0x418
...
0x50C
PRELIMINARY—SUBJECT TO CHANGE WITHOUT NOTICE
Processor 32-Bit Address
0x0000_1000
0x0000_1004
0x0000_1008
0x0000_100C
0x0000_1010
0x0000_1014
0x0000_1018
0x0000_101C
0x0000_1020
0x0000_1024
0x0000_1028
0x0000_102C
0x0000_1040
0x0000_1050
0x0000_1060
...
0x0000_1430
Chapter 5. Arc Four Execution Unit
Register
Control
Status
Clear interrupt
Key Length
Key Low
Key Lower-Middle
Key Upper-Middle
Key Upper
Message Byte Double Word
Plaintext-in
Ciphertext-out
S-box I/J
SBox [0]
SBox [1]
SBox [2]
...
SBox [63]
Type
W
R
W
W
W
W
W
W
W
W
R
R/W
R/W
R/W
R/W
...
R/W
5-1