Stmicroelectronics S.r.l.

Sgs-thomson Microelectronics S.r.l.

Cosimo Torelli

Danilo Rimondi

Carolina Selva

Rita Zappa

Nicola Zatelli

Elisabetta Palumbo

Michele Taliercio

Andrea Baroni

Giovanni Mastrodomenico

Massimo Atti

An electronic device for executing a reliability test. Such an electronic device includes a circuit for implementing a functionality of the electronic device, and testing circuit for executing a test of the functional circuit including a plurality of test operations on the functional circuit. The testing circuit returns an indication of a result of each test operation. In an embodiment, the electronic device further includes control circuit for causing the testing circuit to reiterate the test, monitoring circuit for monitoring the result of each test operation to detect a failure of the test operation, and storage circuit for storing failure information indicative of temporal characteristics of each failure.

Reliability test with monitoring of the results

A method is for making an integrated circuit with built-in self-test. The method includes forming at least one nonvolatile read only memory (ROM) to store ROM code and forming a logic self-test circuit to verify a correct functioning of the at least one nonvolatile ROM. Moreover, the method includes defining, in the logic self-test circuit, a logic self-test core to process the ROM code and to generate a flag based upon a control signature and defining, in the logic self-test circuit, a nonvolatile storage block, coupled to the logic self-test core, to store the control signature. Furthermore, the method includes writing the ROM code to the at least one nonvolatile ROM and writing the control signature to the nonvolatile storage block, during a same fabrication step.

Process and system for the verification of correct functioning of an on-chip memory

A self diagnosis (BISD) device for a random memory array, preferably integrated with the random access memory, executes a certain number of predefined test algorithms and identifies addresses of faulty locations. The BISD device recognizes certain fail patterns of interest and generates bit-strings corresponding to them. In practice, the BISD device may diagnose memory arrays and allow the identification of defects in the production process that affect a new technology during its learning phase, thus accelerating its maturation.

Built-in self diagnosis device for a random access memory and method of diagnosing a random access

A built-in self-test and self-repair structure (BISR) of memory arrays embedded in an integrated device includes at least a test block (BIST) programmable to execute on a respective memory array of the device any of a certain number of test algorithms, and a self-repair block that includes a column address generator processing the faulty address information for allocating redundant resources of the tested memory array. The BISR may further include a redundancy register on which final redundancy information is loaded at each power-on of the device and control logic for managing data transfer from external circuitry to the built-in self-test and self-repair structure (BISR) and vice versa. The BIST structure serves any number of embedded memory arrays even of different types and sizes.

Programmable multi-mode built-in self-test and self-repair structure for embedded memory arrays

A memory cell comprises a first and a second inverters connected in a latch configuration. The inverters have respective first and second means for receiving a first and a second voltage supplies, respectively. The cell also comprises means, responsive to a memory cell selection signal, for selectively connecting an input of at least one of the first and second inverter to at least one respective input/output data line, carrying an input datum to be written in the memory cell in a memory cell write operation and an output datum read from the memory cell in a memory cell read operation. For flash-clearing the memory cell, means are provided for switching at least one of the first and second voltage supply receiving means of at least one of the first and second inverters between the first voltage supply and the second voltage supply. The memory cell is particularly adapted to implement a flash-clear function in a memory device.

Static RAM with flash-clear function

A lateral DMOS transistor having a drain region which comprises a high-concentration portion with which the drain electrode is in contact and a low-concentration portion which is delimited by the channel region. In addition to the conventional source, drain, body and gate electrodes, the transistor has an additional electrode in contact with a point of the low-concentration portion of the drain region which is close to the channel. The additional electrode permits a direct measurement of the electric field in the gate dielectric and thus provides information which can be used both for characterizing the transistor and selecting its dimensions and for activating devices for protecting the transistor and/or other components of an integrated circuit containing the transistor.

Lateral DMOS transistor with first and second drain electrodes in respective contact with high-and low-concentration portions of a drain region

A memory device comprises an array of memory cells arranged in rows and columns, a plurality of gates for transmitting respective selection outputs of a row decoder to respective rows, a dummy column of dummy memory cells substantially identical to the memory cells, precharge means for precharging the columns and the dummy column at a precharge potential when no row is selected, and programming means for setting selected columns at respective programming potentials. The device comprises dummy memory cell preset means for presetting the dummy memory cells in a first logic state when no row is selected, dummy column programming means for setting the dummy column at a prescribed programming potential corresponding to a second logic state opposite to the first logic state, and first detector means for detecting that the dummy column has discharged from the precharge potential to the prescribed programming potential and for consequently enabling said plurality of gates. Each of the gates has an input coupled to a respective dummy memory cell so that the gate is disabled as soon as the respective dummy memory cell has switched from the first logic state to the second logic state.

Memory device with reduced power dissipation

The invention relates to a memory comprising a matrix of memory cells; a plurality of gates for transmitting respective selection outputs of a row decoder to respective rows of the matrix; a dummy bit line having an equivalent load as bit lines associated to columns of the matrix and which is discharged by a dummy memory cell when any row is selected; and circuitry for precharging the bit lines and the dummy bit line when no row is selected, and enabling said gates for transmission of the selection outputs of the row decoder in response to a clock signal. Each gate has an input coupled to the dummy bit line such that the gate is disabled as soon as the dummy bit line has discharged to a switching threshold of the gate.

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Cernusco sul Naviglio, Italy

Cosimo Torelli