Abstract: System-accessible frequency measuring circuits and procedures permit on-chip testing of the oscillators and provide test results observable off chip via LSSD scan paths. This allows a rapid ensemble of ring oscillators in a standard ASIC test flow without the need for on chip analog test equipment (the test apparatus has effectively been created on device and can be digitally configured, operated and read). Frequency measuring logic that can 1) functionally operate to measure the frequency of the ring oscillators; 2) participate in traditional logical tests such as LSSD and LBIST to verify that the circuit is manufactured correctly and is likely to operate and 3) operate in a special ring-oscillator test mode, that allows the logic to operate on a tester very similarly to the way it does functionally. In this mode, the frequency measuring logic can be scanned to a specific state, started by pulsing a digital I/O, and the measured analog value can be scanned out sometime later after the test has completed.

Abstract: A method for embedding tamper proof layers and discrete components into a printed circuit board stack-up is disclosed. According to this method, a plating mask is applied on a base substrate to cover partially one of its faces. Conductive ink is then spread on this face so as to fill the gap formed by the plating mask. To obtain a uniform distribution of the conductive ink and then gel it, the conductive ink is preferably heated. A dielectric layer is applied on the conductive ink layer and the polymerization process is ended to obtain a strong adhesion between these two layers. In a preferred embodiment, conductive tracks are simultaneously designed on the other face of the base substrate to reduce thermo-mechanical strains and deformations.

Abstract: System-accessible frequency measuring circuits and procedures permit on-chip testing of the oscillators and provide test results observable off chip via LSSD scan paths. This allows a rapid ensemble of ring oscillators in a standard ASIC test flow without the need for on chip analog test equipment (the test apparatus has effectively been created on device and can be digitally configured, operated and read). Frequency measuring logic that can 1) functionally operate to measure the frequency of the ring oscillators; 2) participate in traditional logical tests such as LSSD and LBIST to verify that the circuit is manufactured correctly and is likely to operate and 3) operate in a special ring-oscillator test mode, that allows the logic to operate on a tester very similarly to the way it does functionally. In this mode, the frequency measuring logic can be scanned to a specific state, started by pulsing a digital I/O, and the measured analog value can be scanned out sometime later after the test has completed.

Abstract: A physically secure processing assembly is provided that includes dies mounted on a substrate so as to sandwich the electrical contacts of the dies between the dies and the substrate. The substrate is provided with substrate contacts and conductive pathways that are electrically coupled to the die contacts and extend through the substrate. Electrical conductors surround the conductive pathways. A monitoring circuit detects a break in continuity of one or more of the electrical conductors, and preferably renders the assembly inoperable. Preferably, an epoxy encapsulation is provided to prevent probing tools from being able to reach the die or substrate contacts.

Abstract: A method and apparatus is disclosed for preventing the unintended retention of secret data caused by preferred state/burn in secure electronic modules. Sequentially storing the data, and its inverse on alternating clock cycles, and by actively overwriting it to destroy it, prevents SRAM devices from developing a preferred state. By encrypting a relatively large amount of secret data with a master encryption key, and storing said master key in this non-preferred state storage, the electronic module conveniently extends this protection scheme to a large amount of data, without the overhead of investing or actively erasing the larger storage area.

Abstract: A physically secure processing assembly is provided that includes dies mounted on a substrate so as to sandwich the electrical contacts of the dies between the dies and the substrate. The substrate is provided with substrate contacts and conductive pathways that are electrically coupled to the die contacts and extend through the substrate. Electrical conductors surround the conductive pathways. A monitoring circuit detects a break in continuity of one or more of the electrical conductors, and preferably renders the assembly inoperable. Preferably, an epoxy encapsulation is provided to prevent probing tools from being able to reach the die or substrate contacts.