Stmicroelectronics S.r.l.

Stmicroelectrics S.r.l.

Antonino Geraci

Lorenzo Bedarida

Simone Bartoli

Marco Sforzin

Mauro Luigi Sali

Carlo Lisi

Vincenzo Dima

Emanuele Confalonieri

Alberto Campisi

An autotesting method of a cells matrix of a memory device includes the steps of reading the values contained in a plurality of the memory cells, comparing the read values with reference values, signaling mismatch of the read values with the reference values as an error situation, and storing the error situations. In the autotesting method, the reading, comparing, signaling, and storing steps are repeated for all the memory cells in a matrix column. The autotesting method further includes the steps of storing the positions of any columns having at least one error situation, and repeating all of the preceding steps for all the matrix columns.

Autotesting method of a memory cell matrix, particularly of the non-volatile type

An electrically alterable semiconductor memory comprises at least two substantially independent memory banks, and a first control circuit for controlling operations of electrical alteration of the content of the memory. The first control circuit permits the selective execution of an operation of electrical alteration of the content of one of the at least two memory banks. The memory also comprises second control circuit that permits, simultaneously with said operation of electrical alteration of the content of one of the at least two memory banks, a burst mode, page mode, or standard read operation for reading the content of the other memory bank.

Non-volatile memory with functional capability of simultaneous modification of the content and burst mode read or page mode read

A read control circuit and a reading method for an electronic memory device integrated on a semiconductor includes a non-volatile memory matrix with associated row and column decoders connected to respective outputs of an address counter. An address transition detect (ATD) circuit detects an input transition as the memory device is being accessed, and read amplifiers and attendant registers transfer the data read from the memory matrix to the output. The read control circuit includes a detection circuit to which is input a clock signal and a logic signal to enable reading in the burst mode. A burst read mode control logic circuit is connected downstream of the detection circuit. The method includes accessing the memory matrix in a random read mode, detecting a request for access in the burst read mode, and executing the parallel reading of a plurality of memory words during a single period of time clocked by the clock signal.

Non-volatile memory device with burst mode reading and corresponding reading method

Described herein is an output buffer including an output stage formed by a pull-up transistor and a pull-down transistor, which are connected in series between a supply line set at a supply potential and a ground line set at a ground potential, with an intermediate node connected to the output of the output buffer. The output buffer further includes a unidirectional decoupling stage arranged between the output of the output buffer and the pull-up transistor for decoupling the output from the supply line during the switching transients of the output buffer in such a way as to prevent the switching noise present on the latter from being transferred onto the output of the output buffer.

Output buffer for a nonvolatile memory with output signal switching noise reduction, and nonvolatile memory comprising the same

The present invention relates a circuit arrangement for the lowering of the threshold voltage of a diode configured transistor comprising a mirror transistor, a first transistor and a second transistor, said mirror transistor and said first transistor having in common the gate electrodes in a circuit node, said second transistor being connected in a transdiode configuration and placed between the gate electrode and the drain electrode of said first transistor, and a current source being connected to the gate electrode of said first transistor and to the drain electrode of said second transistor, characterized by comprising a third transistor which is configured to receive a switching signal at its gate electrode and is connected between the drain and the gate electrode of said first transistor.

Circuit arrangement for the lowering of the threshold voltage of a diode configured transistor

A direct-comparison reading circuit for a nonvolatile memory array having a plurality of memory cells arranged in rows and columns, and at least one bit line, includes at least one array line, selectively connectable to the bit line, and a reference line; a precharging circuit for precharging the array line and reference line at a preset precharging potential; at least one comparator having a first terminal connected to the array line, and a second terminal connected to the reference line; and an equalization circuit for equalizing the potentials of the array line and reference line in the precharging step. In addition, the reading circuit includes an equalization line distinct from the reference line; and controlled switches for connecting, in the precharging step, the equalization line to the array line and to the reference line, and for disconnecting the equalization line from the array line and from the reference line at the end of the precharging step.

Direct-comparison reading circuit for a nonvolatile memory array

An output buffer device having first and second supply voltage references, the first voltage reference being lower in value than the second voltage reference. The output buffer device includes first and second complementary MOS transistors, which transistors are connected in series together between one of the supply voltage references and a further voltage reference, have gate terminals connected together and to an input terminal of this buffer device, and have drain terminals connected together and to an output terminal of the buffer device. Advantageously, the first transistor is connected to the first supply voltage reference. Furthermore, the output buffer device comprises at least one additional drive MOS transistor of the same type as the first MOS transistor and placed between the second supply voltage reference and the output terminal of the buffer device.

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Monza, Italy

Antonino Geraci