Stmicroelectronics S.r.l.

Emanuela Calvetti

Marcella Carissimi

Marco Pasotti

Fabio Enrico Carlo Disegni

Cesare Torti

Laura Capecchi

Federico Goller

Chantal Auricchio

Davide Manfre'

Stefano Zanchi

A memory device includes programmable memory cells and a programming circuit for programming a selected memory cell to a target logic state by applying one or more programming current pulses. A temperature sensor operates to sense a temperature of the memory device. A reading circuit reads a current logic state of the selected memory cell after a predetermined programming current pulse of the programming current pulses. The reading circuit includes a sensing circuit that senses a current logic state of the selected memory cell according to a comparison between a reading electric current depending on the current logic state of the selected memory cell and a reference current. An adjusting circuit adjusts one or the other of the reading electric current and the reference electric current to be provided to the sensing circuit according to the temperature of the memory device.

Memory device

A method for programming a phase-change-memory device of a differential type comprises, in a first programming mode, supplying, during a first time interval, a same first programming current, of a type chosen between a SET current and a RESET current, to all the direct and complementary memory cells that are to be programmed with said first programming current; and, in a second programming mode, supplying, during a second time interval, a same second programming current, of the other type chosen between a SET current and a RESET current, to all the direct and complementary memory cells that are to be programmed with said second programming current, thus completing, in just two time steps, writing of a logic word in the memory device.

Method for programming a phase-change memory device of differential type, memory device, and electronic system

In accordance with an embodiment, a memory includes: a memory element, a sense amplifier circuit configured to sense a difference during a sense operation between a sense current passing through the memory element and a reference current, and a margin current branch coupled in parallel with the memory element and configured to selectively add a margin current to the sense current.

Memory with margin current addition and related methods

An embodiment method includes storing, in each of a first plurality of memory locations of a memory, an address of another of the first plurality of memory locations, and reading, from a bus signal received at the memory, an address of a first one of the first plurality of memory locations. The method further includes reading data stored in the first one of the first plurality of memory locations, and determining, using the read data, whether a read error has occurred.

System and method of determining memory access time

In accordance with an embodiment, a circuit includes a sense amplifier circuit configured to sense a difference between a first current based on a direct memory bit and a second current based on a complementary memory bit. The direct memory bit is coupled to a first input of the sense amplifier circuit, and the complementary memory bit is coupled to a second input of the sense amplifier circuit. A controller is configured to, during a sense operation, selectively add a first margin current to the first current, and during the sense operation, selectively add a second margin current to the second current.

A differential PCM memory may include first and second PCM elements, and a sense amplifier circuit configured to sense a difference between first and second sense currents passing through the first and second PCM elements, respectively, during a sense operation. The differential PCM memory may include a first margin current branch coupled in parallel with the first PCM element and configured to selectively add a first margin current to the first sense current, and a second margin current branch coupled in parallel with the second PCM element and configured to selectively add a second margin current to the second sense current.

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Villa D'adda, Italy

Emanuela Calvetti