Patent ID: 8341419

Claim:
A microprocessor having a control register to which the manufacturer of the microprocessor may limit access, the microprocessor comprising: a manufacturing identifier, that uniquely identifies the microprocessor, wherein the manufacturing identifier is externally readable from the microprocessor by a user; a secret key, manufactured internally within the microprocessor, wherein the secret key is externally invisible; an encryption engine, coupled to the secret key, configured to decrypt a user-supplied password using the secret key to generate a decrypted result in response to a user instruction instructing the microprocessor to access the control register, wherein the user-supplied password is unique to the microprocessor; and an execution unit, coupled to the manufacturing identifier and the encryption engine, configured to allow the instruction access to the control register if the manufacturing identifier is included in the decrypted result, and to otherwise deny the instruction access to the control register.