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Ferdinando Bedeschi
Ferdinando Bedeschi US
| Patent application number | Description | Published |
|---|---|---|
| 20100165712 | METHOD FOR LOW-STRESS MULTILEVEL READING OF PHASE CHANGE MEMORY CELLS AND MULTILEVEL PHASE CHANGE MEMORY - According to a method for multilevel reading of a phase change memory cell a bit line ( | 07-01-2010 |
| 20110080777 | Adaptive Wordline Programming Bias of a Phase Change Memory - The leakage current and power consumption of phase change memories may be reduced using adaptive word line biasing. Depending on the particular voltage applied to the bitline of a programmed cell, the word lines of unselected cells may vary correspondingly. In some embodiments, the word line voltage may be caused to match the bitline voltage of the programmed cell. | 04-07-2011 |
Ferdinando Bedeschi, Monza IT
| Patent application number | Description | Published |
|---|---|---|
| 20090109738 | PHASE-CHANGE MEMORY DEVICE WITH ERROR CORRECTION CAPABILITY - A phase-change memory device includes a plurality of data PCM cells for storing data bits; data decoding circuits for selectively addressing sets of data PCM cells; and data read/program circuits for reading and programming the selected data PCM cells. The device further includes a plurality of parity PCM cells for storing parity bits associated with data bits stored in the data PCM cells; parity decoding circuits for selectively addressing sets of parity PCM cells; and parity read/program circuits for reading and programming the selected parity PCM cells. | 04-30-2009 |
| 20100128517 | PHASE-CHANGE MEMORY DEVICE WITH DISCHARGE OF LEAKAGE CURRENTS IN DESELECTED BITLINES AND METHOD FOR DISCHARGING LEAKAGE CURRENTS IN DESELECTED BITLINES OF A PHASE-CHANGE MEMORY DEVICE - A phase change memory device includes a bitline biasing unit; and a bitline selection unit connecting a selected bitline to the bitline biasing unit and disconnecting deselected bitlines from the bitline biasing unit in an operative condition. A bitline discharge unit is connected to the bitlines to discharge leakage currents in the bitlines. The bitline discharge unit has a voltage regulation unit and a plurality of bitline discharge switches coupled between the voltage regulation unit and a respective bitline. The bitline discharge switches are controlled to connect the deselected bitlines to the voltage regulation unit and to disconnect the selected bitline from the voltage regulation unit. The voltage regulation unit comprises a PMOS transistor coupled between a regulated voltage bus and a reference potential line. The regulated voltage bus is connected to the bitline discharge switches and the control terminal of the PMOS transistor is biased to a constant voltage. | 05-27-2010 |
| 20100141335 | CURRENT MIRROR CIRCUIT, IN PARTICULAR FOR A NON-VOLATILE MEMORY DEVICE - A current mirror circuit is provided with a first current mirror including a first and a second mirror transistors sharing a common control terminal; the first mirror transistor has a conduction terminal for receiving, during a first operating condition, a first reference current, and the second mirror transistor has a respective conduction terminal for providing, during the first operating condition, a mirrored current based on the first reference current. The current mirror circuit is provided with a switching stage operable to connect the control terminal to the conduction terminal of the first mirror transistor during the first operating condition, and to disconnect the control terminal from the same conduction terminal of the first mirror transistor, and either letting it substantially floating or connecting it to a reference voltage, during a second operating condition, in particular a condition of stand-by. | 06-10-2010 |
| 20100165714 | METHOD OF STORING AN INDICATION OF WHETHER A MEMORY LOCATION IN PHASE CHANGE MEMORY NEEDS PROGRAMMING - A phase change memory includes a float buffer which stores the result of a comparison between the current state of data in the phase change memory cells and an intended next state of each of those cells. The float buffer indicates which cells need to be programmed in order to achieve the new states and which cells happen to already be in the new states. Then, after programming of the cells, the float buffer indicates which cells still need to be programmed. Thus, a control stage uses the information in the float buffer to program only those cells whose states need to be changed. | 07-01-2010 |
| 20100284212 | METHOD FOR MULTILEVEL PROGRAMMING OF PHASE CHANGE CELLS USING ADAPTIVE RESET PULSES - A method for programming multilevel PCM cells envisages: forming an amorphous region of amorphous phase change material in a storage element of a PCM cell by applying one or more reset pulse; and forming a conductive path of crystalline phase change material through the amorphous region by applying one or more set pulse, a size of the conductive path defining a programmed state of the PCM cell and an output electrical quantity associated thereto, and being controlled by the value of the reset pulse and set pulse. The step of forming an amorphous region envisages adaptively and iteratively determining, during the programming operations, a value of the reset pulse optimized for electrical and/or physical properties of the PCM cell, and in particular determining a minimum amplitude value of the reset pulse, which allows programming a desired programmed state and a desired value of the output electrical quantity. | 11-11-2010 |
Ferdinando Bedeschi, Biassono (mi) IT
| Patent application number | Description | Published |
|---|---|---|
| 20100165725 | RELIABLE SET OPERATION FOR PHASE-CHANGE MEMORY CELL - A Phase-Change Memory (PCM) device and a method of writing data to the PCM device are described. The PCM device includes a multi-phase data storage cell having at least a Set state and a Reset state that may be established using a heater configured to heat the data storage cell. A memory interface may be coupled with the heater configured to write data to the data storage cell, the data being represented by the Set or the Reset states. A write Reset pulse is used to place the data storage cell in the Reset state corresponding to a read value that is less than a read threshold. A write Set pulse that is a predetermined function of the write Reset pulse is used to place the data storage cell in the Set state. The PCM device may include additional intermediate states that enable each data storage cell to store two or more bits of information. Other embodiments may be described and claimed. | 07-01-2010 |
Ferdinando Bedeschi, Biassono IT
| Patent application number | Description | Published |
|---|---|---|
| 20100169740 | ACCELERATING PHASE CHANGE MEMORY WRITES - In a phase change memory, the memory array may be written in relatively small chunks. The writing of data to the array and, particularly, the writing of set data, may be accelerated using a hardware accelerator. The hardware accelerator may include an edge detector which detects a short duration signal pulse to trigger the writing of the set data to a cell. As a result, the writing of data may be accelerated, reducing the time to write in some cases. | 07-01-2010 |
| 20110113303 | METHOD AND APPARATUSES FOR CUSTOMIZABLE ERROR CORRECTION OF MEMORY - Described herein are a method and apparatuses for providing customizable error correction for memory arrays. In one embodiment, an apparatus includes a memory device having a memory array to store data and an analog to digital sense unit coupled to the memory array. The analog to digital sense unit senses analog signals associated with the memory array and converts the analog signals into distributions of digital values. An error-correcting code (ECC) unit receives the distributions of digital values from the analog to digital sense unit. A configurable non-volatile look-up table generates ECC parameters including error probability data and provides the ECC parameters to the ECC unit for error correction. The error probability data has error probability values that are associated with the distributions of digital values. The ECC unit executes an ECC algorithm to provide error correction using the error probability data. | 05-12-2011 |
Ferdinando Bedeschi, Agrate Brianza IT
| Patent application number | Description | Published |
|---|---|---|
| 20090285016 | Circuit for Reading Memory Cells - A read circuit for reading at least one memory cell adapted to storing a logic value, the at least one memory cell including: a storage element made of a phase-change material; and an access element for coupling the storage element to the read circuit in response to a selection of the memory cell, the read circuit including: a sense current supply arrangement for supplying a sense current to the at least one memory cell; and at least one sense amplifier for determining the logic value stored in the memory cell on the basis of a voltage developing thereacross, the at least one sense amplifier comprising a voltage limiting circuit for limiting the voltage across the memory cell for preserving the stored logic value, wherein the voltage limiting circuit includes a current sinker for sinking a clamping current, which is subtracted from the sense current and depends on the stored logic value. | 11-19-2009 |
Ferdinando Bedeschi, Milano IT
| Patent application number | Description | Published |
|---|---|---|
| 20080232171 | Phase change memory with program/verify function - A phase change memory includes a plurality of cells for storing data in the form of respective resistance levels, addressing circuits for addressing cells to be programmed, and the resistance levels are determined from comparison of cell currents of addressed cells with a reference current. A reference generator provides the sense amplifier with the reference current. The reference generator is provided with a reference select circuit to select the reference current from a plurality of verify currents based on program data to be stored in the cell. | 09-25-2008 |
| 20090256133 | Multiple layer resistive memory - A resistive memory cell may be composed of four stacked layers. Each layer may be sandwiched by electrodes. Connections may be formed from each of four directions around the stack, for example, aligned with each of four edges where the resistive layers are rectangular. | 10-15-2009 |
Ferdinando Bedeschi, Milan IT
| Patent application number | Description | Published |
|---|---|---|
| 20090116281 | Reading Phase Change Memories - A read current high enough to threshold a phase change memory element may be used to read the element without thresholding the memory element. The higher current may improve performance in some cases. The memory element does not threshold because the element is read and the current stopped prior to triggering the memory element. | 05-07-2009 |