54.5.5.6 Stop Operation

The Stop operation removes sensitive data from the PUF controller and the PUF SRAM, and sets the PUF controller to the Stopped state. After this command has finished, key operations can no longer be performed. This can be used when no key operations are expected for an extended period of time (e.g. when the system goes into Sleep mode), and ensures that the intrinsic PUF key is only present in the system when needed, which improves security.

If key operations need to be performed again after a Stop operation, then a Start or Reconstruct operation needs to be completed first, as explained in PUF Controller States.