Electronic key with three modes of automatic self-disablement

摘要

An integrated circuit with three independently programmable "time bomb" functions. The integrated circuit can be set to disable itself after a certain number of power-up cycles, or after a certain total duration of operation, or after a certain absolute time and date. This is particularly advantageous for authorization functions, where the manufacturer may want to enable the user to "test drive" a demonstration or rental item of hardware or software.