SDC Constraint, Input / Output Delay
Preparing IO constraint for FPGA is always a tedious job. And the following is a spreadsheet to help the number crunching. BTW, I have to say that MS Excel is much more powerful than Google Spreadsheet.
AES and Encryption in China
AES is a popular encryption algorithm with symmetric keys. If you are looking for open source AES implementions, Ref  is one of them.
To verify the AES implementation is in line with National Standard, use the test vectors from Ref as passing criteria.
BTW, China has its own flavor of encryption product regulation (Ref). Ask Office of Security Commercial Code Administration (OSCCA) before the police knocking on your door. I'm not kidding, and HP knows it all well :-( (Ref).
 Ilya Levin, a byte-oriented aes-256 implementation
 Morris Dworkin, Recommendation for Block Cipher Modes of Operation, Methods and Techniques, NIST, 2001
 Xia Yu and Matthew Murphy, The Regulation of Encryption Products in China, MMLC Group
 CHINA’S EXPORT CONTROLS AND ENCRYPTION REGULATIONS
 Mr.王掌柜, 中国有趣的“商用密码管理”
 个人使用密码产品，例如 OpenSSL，是否属于违法行为?
*) Legal Disclaimer
*) The Book
*) FPGA Limerick
*) FCC Wireless
*) PAPA System