The NIST has selected cipher Rijndael as AES on October 20, 2000 based on the combination security, performance, efficiency, ease of implementation and flexibility. The algorithm has been designed by Joan Daemen and Vincent Rijmen. Rijndael is a symmetric-key iterated block cipher, length of the block is 128 bits and length of the key can be specified to be 128, 192 bit, 256 bits.
The core complies to FIPS 197. This document can be downloaded here : FIPS 197