Abstract: Provided is a non-destructive method of detecting die crack problems in an integrated circuit. The method provides for testing for die crack problems in all chips and in many production chips without adding any extra circuitry or pads. In a preferred embodiment, the method takes advantage of an existing NAND gate tree structure at the perimeter of many conventional dies, although the invention is also applicable to other logic gate structures that may exist or may be formed at the perimeter of dies. The invention recognizes that this NAND gate tree structure may be used in order to identify and localize die cracks in finished chips, thereby providing a faster, more accurate and nondestructive way to test for die cracks in production chips. A typical NAND gate tree structure has the form of a cascade inverter chain. Since one end of the first NAND gate is tied to VDD, the output of each gate will alternate between low and high.

Abstract: A phase-locked loop cell includes a voltage-controlled oscillator adapted to produce an oscillating signal. A test input to the phase-locked loop is adapted to cause the voltage-controlled oscillator to generate a test oscillating signal. A frequency decoder is coupled to the output of the voltage controlled oscillator and is adapted to provide a voltage related to the frequency of the test oscillating signal.

Abstract: Provided is a universal decoder test board (UDTB) capable of performing the package interface and pin scrambling functions of a conventional DUT board with a variety of different package designs. The UDTB is designed such that it is capable of interfacing with a variety of different tester interface boards, each tester interface board associated with its own hardware manufacturer tester. The UDTB significantly reduces the time and expense invested in test boards required for testing semiconductor device packages for a variety of different manufacturers'platforms by allowing a given package type to be tested with a plurality of testers on the same UDTB.