AMD Geode™ LX Processors Data Book 19
Architecture Overview 33234H
2.10 Security Block
The AMDGeode LX processor has an on-chip AES 128-bit
crypto acceleration block capable of 44 Mbps throughput
on either encryption or decryption at a processor speed of
500 MHz. The AES block runs asynchronously to the pro-
cessor core and is DMA based. The AES block supports
both EBC and CBC modes and has an interface for
accessing the optional EEPROM memory for storing
unique IDs and/or security keys. The AES and EEPROM
sections have separate control registers but share a single
set of interrupt registers. The AES module has two key
sources: one hidden 128-bit key stored in the “on-package”
EEPROM, and a write only 128-bit key (reads as all zeros).
The hidden key is loaded automatically by the hardware
after reset and is not visible to the processor. The
EEPROM can be locked. The initialization vector for the
CBC mode can be generated by the True Random Number
Generator (TRNG). The TRNG is addressable separately
and generates a 32-bit random number.