摘要 |
Described are programmable logic devices that decrypt proprietary configuration data using on-chip decryption keys. The keys are stored in a key memory that can be operated in a secure mode or a non-secure mode. The non-secure mode allows the decryption keys to be read or written freely; the secure mode bars read and write access to the decryption keys. The programmable logic device supports secure and non-secure modes on a key-by-key basis, allowing users to write, verify, and erase individual keys without affecting others. |