MCF548x Reference Manual, Rev. 3
22-50 Freescale Semiconductor

22.12 Advanced Encryption Standard Execution Units (AESU)

This section contains details about the Advanced Encryption Standard Execution Units (AESU), including
detailed register map, modes of operation, status and control registers.

22.12.1 AESU Register Map

The registers used in the AESU are documented primarily for debug and target mode operations. If the
SEC requires the use of the AESU when acting as an initiator, accessing these registers directly is
unnecessary. The device drivers and the on-chip controller will abstract register level access from the user.
The AESU contains the following registers:
Reset control register
Status register
Interrupt status register
Interrupt control register

22.12.2 AESU Reset Control Register (AESRCR)

This register allows three levels reset of just AESU, as defined by the three self-clearing bits.
Table 22-33. RNGIMR Field Descriptions
Bits Name Description
31 ME Mode Error. An illegal value was detected in the mode register.
0 Mode error enabled
1 Mode error disabled
30 AE Address Error. An illegal read or write address was detected within the MDEU address
space.
0 Address error enabled
1 Address error disabled
29–26 — Reserved
25 OFU Output FIFO Underflow. RNG Output FIFO has been read while empty.
0 Output FIFO underflow error enabled
1 Output FIFO underflow error disabled
24–21 — Reserved
20 IE Internal Error. An internal processing error was detected while generating random
numbers.
0 Internal error enabled
1 Internal error disabled
19–0 — Reserved