Various techniques permit more thorough development of digital systems and
devices by designers while protecting the proprietary interests of the
owners of the intellectual property incorporated in such systems and
devices. More specifically, the present invention provides to an end
customer IP hardware which is suitable for prototype testing, but
unusable for production purposes. One method limits the physical or
electrical mode of operation of a hardware platform used for prototype
testing of intellectual property (such as limiting the number of
electrical contacts between the hardware and an external electrical
device or limiting the data format(s) usable in the hardware during
prototype testing). Another method limits the temporal operation of a
hardware platform using an internal counter within the software provided
by the intellectual property owner. Once a clock count limit is reached,
the software disables the hardware in one or more prescribed ways, such
as a reset of one or more registers, a global tri-state of the hardware
10, or a random failure of some type. Suitable hardware fabrication
and/or augmentation also may be used to differentiate between the
prototype and production manners of operation.