Abstract:
L'invention concerne une mémoire comprenant au moins une ligne (WLm) à laquelle sont reliées des cellules mémoire. Un circuit de commande est configuré pour émettre un signal de fin d'opération transitoire (OPm) à la fin de l'exécution d'une opération sur au moins une cellule mémoire, et un circuit de détection d'une impulsion transitoire (DC1) relié à la ligne (WLm) de la mémoire est configuré pour fournir un signal de détection d'une impulsion transitoire lorsqu'un front descendant de l'amplitude d'un signal en tension (Csm) apparaît sur la ligne de la mémoire en l'absence du signal de fin d'opération.
Abstract:
An electronic device (22, 48, 50) includes an array (26) of memory cells, which are configured to store data values. One or more sense amplifiers (40) have respective inputs for receiving signals from the memory cells and are configured to output the data values corresponding to the received signals. Switching circuitry (36, 52) is coupled between the array of the memory cells and the sense amplifiers and is configured to receive an indication of a temporal pattern and to route the signals from the memory cells among the inputs of the sense amplifiers in accordance with the temporal pattern.
Abstract:
A method (100) is disclosed of generating an identifier from a semiconductor device (600) comprising a volatile memory (610) having a plurality of memory cells. The method comprises causing (110) the memory cells to assume a plurality of pseudo-random bit values inherent to variations in the microstructure of the memory cells; retrieving (120) the bit values from at least a subset of the plurality of memory cells; and generating the identifier from the retrieved bit values. The method (100) is based on the realization that a substantial amount of the cells of a volatile memory can assume a bit value that is governed by underlying variations in manufacturing process parameters; this for instance occurs at power-up for an SRAM or after a time period without refresh for a DRAM. This can be used for several identification purposes, such as identifying a semiconductor device (600) comprising the volatile memory (610), or for secure key generation by mapping error- correcting code words onto the identifier bit locations. The present invention further includes a semiconductor device (600, 1000) configured to be subjectable to the method (100) of the present invention.
Abstract:
A write protection mechanism may be implemented that is external to a non-volatile memory device (210) and/or that is external to controller/s (220, 230) that interface with the non-volatile memory device (210), thus providing increased security over unauthorized and/or undesirable write cycles to the memory device (210). Write protection security may be further enhanced by providing a write protection control signal (272) that is external to the non-volatile memory and attached memory controller/s (220, 230), thus preventing accidental or intentional override.
Abstract:
Memory block locking apparatus and methods are provided. A method of operating a memory device includes preventing programming of upper and lower bound regions of a memory array of the memory device and any regions of the memory array having addresses between addresses of the upper and lower bound regions or preventing programming of any regions of the memory array having addresses greater than the address of the upper bound region and/or addresses less than the address of the lower bound region.
Abstract:
An integrated circuit having a device with an adjustable parameter utilizes a two signal control protocol to select the device, change the parameter value with or without saving the parameter value in a non-volatile memory, and to write protect the parameter value in the non-volatile memory.
Abstract:
An electronic device for securing the contents of data storage and processing elements. The device includes a security element and a phase-change element connected in a parallel arrangement. The security element is a three-terminal device, such as a conventional transistor or three-terminal phase-change device, having an ON state and an OFF state which differ with respect to resistance and regulate electronic access to the phase-change element by controlling the flow of electrical current applied to the parallel combination. In the ON state, the resistance of the security element is less than that of the phase-change element, thereby preventing, inhibiting or confusion a determination of the resistance of the phase-change element. In this PROTECT mode, the contents of the phase-change element are secured. In the OFF state, the resistance of the security element is greater than that of the phase-change material so that the resistance of the parallel combination approaches that of the phase-change element. In this READ mode, the resistance and information content of the phase-change element can be determined. The phase-change element includes a phase-change material and is preferably a chalcogenide based element. The phase-change element may perform a storage or processing function and includes registers and weighting devices as preferred embodiments.
Abstract:
A memory cell for storing 1-bit data is formed by using at least two memory elements in the OTP type nonvolatile memory using a memory element that have two states and can transit only in one direction. In the OTP type nonvolatile memory using a memory element that has two states of an H state (a first state) and an L ( a second state) state (hereinafter simply referred to as H and L) and can electrically transit only in one direction from L to H, a memory cell for storing 1-bit data is formed by using two or more memory elements.