| Patent application number | Description | Published |
| 20080291719 | Streaming mode programming in phase change memories - A streaming programming mode may be implemented on user command in a phase change memory. In the streaming programming mode, accelerated programming may be achieved by ramping up to a voltage that it used for both reading and programming. Repeated programming operations may be streamed after one ramp up without ramping down the voltage on the memory cells between programming operations. This may save time. In addition, the memory may be read in between programming operations, again, without necessarily ramping down. | 11-27-2008 |
| 20080298122 | Biasing a phase change memory device - A phase change memory device includes a plurality of cells connected to bitlines and including respective phase change memory elements and cell select devices and an addressing circuit for selectively addressing at least one bitline and one cell connected thereto. A reading column bias circuit supplies a bitline voltage to the addressed bitline and cell. The bitline voltage includes the sum of a safe voltage and a reference select device voltage, wherein the reference voltage is equal to a select device voltage on the select device when a cell current flowing through the phase change memory element and the cell select device is equal to a safe current. The safe voltage and the safe current are such that phase transition of the phase change memory element is prevented in any bias condition including a cell voltage lower than the safe voltage and in any bias condition including the cell current lower than the safe current. | 12-04-2008 |
| 20090073751 | Interleaved array architecture - A partition may be made up of two planes of memory cells in a phase change memory. These planes may be configured so that they are not adjacent to one another. In some embodiments, this may mean that the adjacent planes may share sensing circuits, reducing the overall size of the memory array. In addition, by using non-adjacent planes to make up a partition, the planes may be spaced in a way which reduces resistance of power conveying lines. This may mean that smaller sized lines may be used, further reducing the size of the overall array. | 03-19-2009 |
| 20090073752 | 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. | 03-19-2009 |
| 20090080241 | Programming a phase change memory - A programming circuit of a phase change memory cell includes a controllable current generator to supply a programming pulse and an internal control unit coupled to the controllable current generator for stepwise modifying the programming pulse. The internal control unit, in turn, includes a control signal generator to provide the controllable current generator with a plurality of control signals. An oscillator provides a time reference signal and a driving module drives the control signal generator based on the time reference signal. As a result, a programming pulse with stepwise adjustable slope can be produced, including such a pulse with different leading and trailing edges. | 03-26-2009 |
| 20090080242 | Programming a multilevel phase change memory cell - Multilevel phase change memory cells may be programmed forming amorphous regions of amorphous phase change material in a storage region of the phase change memory cell. Crystalline paths of crystalline phase change material are formed through the amorphous regions of amorphous phase change material. Lengths of the crystalline paths are controlled so that at least a first crystalline path has a first length in a first programming state and a second crystalline path has a second length, different from the first length, in a second programming state. | 03-26-2009 |
| 20090080267 | Generating reference currents compensated for process variation in non-volatile memories - In a current reference generator device, a voltage reference generator stage generates a reference voltage (V | 03-26-2009 |
| 20090091988 | Writing bit alterable memories - A bit alterable memory may include current generators in a periphery outside the main memory core. Current may be generated in the periphery and driven into the core. As a result, the capacitance of the memory cells has a lowered effect. The current may be generated using the chip supply voltage and then mirrored using a pump voltage. In some embodiments, the mirroring may be ratioed at the partition level and multiplied at the plane level. A delay may be provided before applying the currents to the cell to accommodate for transients. | 04-09-2009 |
| 20090196092 | Programming bit alterable memories - Program failures during programming can be corrected during reading using an error correcting code. This allows an array to pass programming more readily, speeding the operation of the memory and avoiding the need to continually reprogram or to issue an error message that the programming was unsuccessful. This makes the memory more user friendly and robust. | 08-06-2009 |