Patent application number | Description | Published |
20110078521 | TRANSITION FAULT TESTING FOR A VON-VOLATILE MEMORY - A method is for testing a non-volatile memory. A base data pattern is defined for a first pageset of the non-volatile memory. The non-volatile memory has a plurality of pages which comprise words. The base pattern is arranged so that each bitpair of a plurality of bitpairs that includes one of a group consisting of even bitpairs and odd bitpairs formed from all of the words exhibits all possible bitpair transitions during sequential accesses of the pages of the plurality of pages. The base pattern is stored in the first pageset. The pages of the plurality of pages of the first pageset are accessed sequentially. | 03-31-2011 |
20120014179 | SOFT PROGRAM OF A NON-VOLATILE MEMORY BLOCK - A method includes erasing bits and identifying bits that have been over-erased by the erasing. A first subset of the bits that have been over-erased are soft programmed. The results of soft programming the first subset of bits is measured. An initial voltage condition from a plurality of possible voltage conditions based on the results from soft programming the first subset of bits is selected. A second subset of bits that have been over-erased are soft programmed. The soft programming applies the initial voltage condition to the bits in the second subset of bits. The second subset comprises bits that are still over-erased when the step of selecting occurs. The result is that the soft programming for the second subset may begin at a more optimum point for quickly achieving the needed soft programming to bring all of the bits within the desired erase condition. | 01-19-2012 |
20120072794 | NON-VOLATILE MEMORY (NVM) WITH IMMINENT ERROR PREDICTION - A method and system are provided for determining an imminent failure of a non-volatile memory array. The method includes: performing a first array integrity read of the memory array until an error is detected; determining that the error is not error correction code (ECC) correctable, wherein a first word line voltage associated with the error is characterized as being a first threshold voltage; performing a second array integrity read of the memory array until all bits of the memory array indicate a predetermined state, wherein a second word line voltage associated with all of the bits indicating the predetermined state is a second threshold voltage; and comparing a difference between the first and second threshold voltages to a predetermined value. | 03-22-2012 |
20120113714 | METHOD FOR PROGRAMMING A MULTI-STATE NON-VOLATILE MEMORY (NVM) - A method is provided for programming a multi-state flash memory having a plurality of memory cells. A first programming pulse is provided to the flash array; determining a threshold voltage distribution for the plurality of memory cells after providing the first programming pulse. The plurality of memory cells is categorized into at least two bins based on a threshold voltage of each memory cell of the plurality of memory cells. A first voltage is selected for a second programming pulse for programming a first bin of memory cells of the at least two bins, the first voltage based on both a threshold voltage of the first bin and a first target threshold voltage. A second voltage is selected for a third programming pulse for programming a second bin of memory cells of the at least two bins, the second voltage based on both the threshold voltage of the second bin and on a second target threshold voltage. | 05-10-2012 |
20120117307 | NON-VOLATILE MEMORY (NVM) ERASE OPERATION WITH BROWNOUT RECOVERY TECHNIQUE - A method for erasing a non-volatile memory includes: performing a first pre-erase program step on the non-volatile memory; determining that the non-volatile memory failed to program correctly during the first pre-erase program step; performing a first soft program step on the non-volatile memory in response to determining that the non-volatile memory failed to program correctly; determining that the non-volatile memory soft programmed correctly; performing a second pre-erase program step on the non-volatile memory in response to determining that the non-volatile memory soft programmed correctly during the first soft program step; and performing an erase step on the non-volatile memory. The method may be performed using a non-volatile memory controller. | 05-10-2012 |
20120131262 | Method and Apparatus for EEPROM Emulation for Preventing Data Loss in the Event of a Flash Block Failure - A defect resistant EEPROM emulator ( | 05-24-2012 |
20120201082 | ERASE RAMP PULSE WIDTH CONTROL FOR NON-VOLATILE MEMORY - A method of erasing a memory block of a non-volatile memory, including setting a pulse width of erase pulses to an initial width, repeatedly applying erase pulses to the memory block until the memory block meets an erase metric or until a maximum number of erase pulses have been applied, gradually adjusting a pulse voltage magnitude of the erase pulses from an initial pulse voltage level to a maximum pulse voltage level, and reducing the width of the erase pulses to less than the initial width when the pulse voltage magnitude reaches an intermediate voltage level between the initial pulse voltage level and the maximum pulse voltage level. Thus, narrow pulses are applied at higher voltage levels to reduce the amount of over erasure of the memory block. | 08-09-2012 |
20120206973 | Digital Method to Obtain the I-V Curves of NVM Bitcells - A calibration table ( | 08-16-2012 |
20120327710 | ADAPTIVE WRITE PROCEDURES FOR NON-VOLATILE MEMORY - A method includes performing a write operation on memory cells of a memory array to a first logic state using a voltage of a charge pump. A portion of the write operation is performed on the memory cells of the memory array using the voltage of the charge pump. A level of the voltage is compared to a reference. If the level of the voltage is below the reference, the write operation is continued with an increased level of the voltage by reducing load on the charge pump by providing the voltage on a reduced number of memory cells, wherein the reduced number of memory cells is a first subset of the memory cells. | 12-27-2012 |
20120327720 | ADAPTIVE WRITE PROCEDURES FOR NON-VOLATILE MEMORY USING VERIFY READ - A method includes performing a write operation on memory cells of a memory array to a first logic state using a voltage of a charge pump. A portion of the write operation is performed on the memory cells of the memory array using the voltage of the charge pump. A determination is made if the voltage insufficient for performing the write operation on the memory cells of the memory array. If a level of the voltage is insufficient, the write operation is continued with an increased level of the voltage by reducing load on the charge pump by providing the voltage on a reduced number of memory cells. The reduced number of memory cells is a first subset of the memory cells. | 12-27-2012 |
20130107621 | BUILT-IN SELF TRIM FOR NON-VOLATILE MEMORY REFERENCE CURRENT | 05-02-2013 |
20130194874 | Dynamic Healing Of Non-Volatile Memory Cells - Methods and systems are disclosed for dynamic healing of non-volatile memory (NVM) cells within NVM systems. The dynamic healing embodiments described herein relax damage within tunnel dielectric layers for NVM cells that occurs over time from charges (e.g., holes and/or electrons) becoming trapped within these tunnel dielectric layers. NVM operations with respect to which dynamic healing processes can be applied include, for example, erase operations, program operations, and read operations. For example, dynamic healing can be applied where performance for the NVM system degrades beyond a selected performance level for an NVM operation, such as elevated erase/program pulse counts for erase/program operations and bit errors for read operations. A variety of healing techniques can be applied, such as drain stress processes, gate stress processes, and/or other desired healing techniques. | 08-01-2013 |
20130238831 | METHOD FOR IMPLEMENTING SECURITY OF NON-VOLATILE MEMORY - An integrated circuit includes a non-volatile memory module that can censor access to various memory regions based upon a censorship criteria. Information used to implement the censorship criteria is stored at a non-volatile memory location. A one-time programmable non-volatile memory location stores a value representing permanent censorship key. If the permanent censorship key is in an erased state, one or more resources are allowed to modify the non-volatile memory location and disable censorship. If the permanent censorship key has one or more programmed bits, no resource is allowed to modify the non-volatile memory location and disable censorship. | 09-12-2013 |
20130290797 | NON-VOLATILE MEMORY (NVM) RESET SEQUENCE WITH BUILT-IN READ CHECK - A new, robust non-volatile memory (NVM) reset sequence is provided in accordance with at least one embodiment, which, after reading a Test NVM portion and overwriting NVM configuration registers' default values with the values read from the Test NVM portion, does a read integrity check. If the read integrity check passes, a reset process will conclude. Otherwise, if the read integrity check fails, the reset process will re-try reading the Test NVM and overwriting the NVM configuration registers' default values. If the read integrity check still fails after a maximum number of re-tries, a fail flag will be set, and the predetermined “safe” default values will be reloaded to the NVM configuration registers, thereby assuring that the NVM device is operational. | 10-31-2013 |
20130290808 | ERASING A NON-VOLATILE MEMORY (NVM) SYSTEM HAVING ERROR CORRECTION CODE (ECC) - A method of erasing a non-volatile semiconductor memory device comprising determining a number of bit cells that failed to erase verify during an erase operation. The bit cells are included in a subset of bit cells in an array of bit cells. The method further comprises determining whether an Error Correction Code (ECC) correction has been previously performed for the subset of bit cells. The erase operation is considered successful if the number of bit cells that failed to erase verify after a predetermined number of erase pulses is below a threshold number and the ECC correction has not been performed for the subset of bit cells. | 10-31-2013 |
20130308402 | TEST FLOW TO DETECT A LATENT LEAKY BIT OF A NON-VOLATILE MEMORY - A technique for detecting a leaky bit of a non-volatile memory includes erasing cells of a non-volatile memory. A bias stress is applied to the cells subsequent to the erasing. An erase verify operation is performed on the cells subsequent to the applying a bias stress to the cells. Finally, it is determined whether the cells pass or fail the erase verify operation based on whether respective threshold voltages of the cells are below an erase verify level. | 11-21-2013 |
20130326285 | STRESS-BASED TECHNIQUES FOR DETECTING AN IMMINENT READ FAILURE IN A NON-VOLATILE MEMORY ARRAY - A technique for detecting an imminent read failure in a non-volatile memory array includes applying a bulk read stress to a plurality of cells of the non-volatile memory array and determining whether the plurality of cells exhibit an uncorrectable error correcting code (ECC) read during an array integrity check at a margin read verify voltage level subsequent to the bulk read stress. The technique also includes providing an indication of an imminent read failure for the plurality of cells when the plurality of cells exhibit the uncorrectable ECC read during the array integrity check. In this case, the margin read verify voltage level is different from a normal read verify voltage level. | 12-05-2013 |
20140029351 | METHODS AND SYSTEMS FOR ADJUSTING NVM CELL BIAS CONDITIONS FOR PROGRAM/ERASE OPERATIONS TO REDUCE PERFORMANCE DEGRADATION - Methods and systems are disclosed for adjusting program/erase bias conditions for non-volatile memory (NVM) cells to improve performance and product lifetime of NVM systems. System embodiments include integrated NVM systems having an NVM controller, a bias voltage generator, and an NVM cell array. Further, the NVM systems can store performance degradation information and program/erase bias condition information within storage circuitry. The disclosed embodiments adjust program/erase bias conditions for the NVM cells based upon performance degradation determinations, for example, temperature-based performance degradation determinations and interim verify based performance degradation determinations. | 01-30-2014 |
20140040687 | Non-Volatile Memory (NVM) with Imminent Error Prediction - A non-volatile memory system includes a memory array and a memory controller. The memory controller is configured to perform a first array integrity read operation of the array until an error is detected. The controller is also configured to determine that the error is not error correction code (ECC) correctable. A first word line voltage associated with the error is characterized as being a first threshold voltage. The controller is further configured to perform a second array integrity read operation of the array. The second array integrity read operation includes reading the array with a word line read voltage that is offset from the first threshold voltage and is based on a predetermined width offset reference value. Finally, the controller is configured to check a check sum value resulting from the second array integrity read operation to determine when an imminent failure in the memory array is indicated. | 02-06-2014 |
20140078829 | NON-VOLATILE MEMORY (NVM) WITH ADAPTIVE WRITE OPERATIONS - A method of performing a write operation on memory cells of a memory array includes applying a first plurality of pulses the write operation on the memory cells in accordance with a first predetermined ramp rate, wherein the first plurality of pulses is a predetermined number of pulses; performing a comparison of a threshold voltage of a subset of the memory cells with an interim verify voltage; and if a threshold voltage of any of the subset of memory cells fails the comparison with the interim verify voltage, continuing the write operation by applying a second plurality of pulses on the memory cells in accordance with a second predetermined ramp rate which has an increased ramp rate as compared to the first predetermined ramp rate. | 03-20-2014 |
20140098615 | LATENT SLOW BIT DETECTION FOR NON-VOLATILE MEMORY - In accordance with at least one embodiment, a non-volatile memory (NVM) and method is disclosed for detecting latent slow erase bits. At least a portion of an array of NVM cells is erased with a reduced erase bias. The reduced erase bias has a reduced level relative to a normal erase bias. A least erased bit (LEB) threshold voltage level of the least erased bit (LEB) is determined. An erase verify is performed at an adjusted erase verify read threshold voltage level. The adjusted erase verify read threshold voltage level is a predetermined amount lower than the LEB read threshold voltage level. A number of failing bits is determined. The failing bits are bits with a threshold voltage above the adjusted erase verify level. The NVM is rejected in response to the number of failing bits being less than a failing bits threshold. | 04-10-2014 |
20140136928 | PROGRAMMING A NON-VOLATILE MEMORY (NVM) SYSTEM HAVING ERROR CORRECTION CODE (ECC) - A method of programming a non-volatile semiconductor memory device includes determining a number of bit cells that failed to program verify during a program operation. The bit cells are included in a subset of bit cells in an array of bit cells. The method further determines whether an Error Correction Code (ECC) correction has been previously performed for the subset of bit cells. The program operation is considered successful if the number of bit cells that failed to program verify after a predetermined number of program pulses is below a threshold number and the ECC correction has not been performed for the subset of bit cells. | 05-15-2014 |
20140160869 | BUILT-IN SELF TRIM FOR NON-VOLATILE MEMORY REFERENCE CURRENT - A non-volatile memory built-in self-trim mechanism is provided by which product reliability can be improved by minimizing drift of reference current used for accessing the non-volatile memory and for performing initial trimming of the reference current. Embodiments perform these tasks by using an analog-to-digital converter to provide a digital representation of the reference current (Iref) and then comparing that digital representation to a stored target range value for Iref and then adjusting a source of Iref accordingly. For a reference current generated by a NVM reference bitcell, program or erase pulses are applied to the reference cell as part of the trimming procedure. For a reference current generated by a bandgap-based circuit, the comparison results can be used to adjust the reference current circuit. In addition, environmental factors, such as temperature, can be used to adjust the measured value for the reference current or the target range value. | 06-12-2014 |
20140204678 | DYNAMIC DETECTION METHOD FOR LATENT SLOW-TO-ERASE BIT FOR HIGH PERFORMANCE AND HIGH RELIABILITY FLASH MEMORY - A method and apparatus for detecting a latent slow bit (e.g., a latent slow-to-erase bit) in a non-volatile memory (NVM) is disclosed. A maximum number of soft program pulses among addresses during an erase cycle is counted. In accordance with at least one embodiment, a number of erase pulses during the erase cycle is counted. In accordance with various embodiments, determinations are made as to whether the maximum number of the soft program pulses has increased at a rate of at least a predetermined minimum rate comparing to a previous erase cycle, whether the maximum number of the soft program pulses has exceeded a predetermined threshold, whether the number of erase pulses has increased comparing to a previous erase cycle, or combinations thereof. In response to such determinations, the NVM is either passed or failed on the basis of the absence or presence of a slow bit in the NVM. | 07-24-2014 |
20140254285 | Temperature-Based Adaptive Erase or Program Parallelism - A method includes, in one implementation, performing a memory operation to place memory cells of a memory array to a first logic state using a voltage of a charge pump. A portion of the operation is performed on the memory cells using the voltage of the charge pump. A temperature of the memory array is compared to a threshold. If the temperature is above a reference level, a load on the charge pump is reduced by providing the voltage to only a reduced number of memory cells. | 09-11-2014 |
20140269111 | NON-VOLATILE MEMORY (NVM) WITH BLOCK-SIZE-AWARE PROGRAM/ERASE - A memory includes a plurality of blocks in which each block includes a plurality of memory cells. The memory includes a set of charge pumps which apply voltages to the plurality of blocks. A method includes selecting a block of the plurality of memory blocks; determining an array size of the selected block; determining a set of program/erase voltages based on the array size and temperature from a temperature sensor; and programming/erasing the selected block, wherein the set of program/erase voltages are applied by the set of charge pumps during the programming/erasing of the selected block. | 09-18-2014 |
20150023106 | Adaptive Erase Recovery For Non-Volatile Memory (NVM) Systems - Methods and systems are disclosed for adaptive erase recovery of non-volatile memory (NVM) cells within NVM systems. The adaptive erase recovery embodiments adaptively adjust the erase recovery discharge rate and/or discharge time based upon the size of NVM block(s) being erased and operating temperature. In one example embodiment, the erase recovery discharge rate is adjusted by adjusting the number of discharge transistors enabled within the discharge circuitry, thereby adjusting the discharge current for erase recovery. A lookup table is used to store erase recovery discharge rates and/or discharge times associated with NVM block sizes to be recovered and/or operating temperature. By adaptively controlling erase recovery discharge rates and/or times, the disclosed embodiments improve overall erase performance for a wide range of NVM block sizes while avoiding possible damage to high voltage circuitry within the NVM system. | 01-22-2015 |
20150049555 | Extended Protection For Embedded Erase Of Non-Volatile Memory Cells - Methods and systems are disclosed for extended erase protection for non-volatile memory (NVM) cells during embedded erase operations for NVM systems. The embodiments described herein utilize an additional threshold voltage (Vt) check after soft programming operation within an embedded erase operation completes to provide extended erase protection of NVM cells. In particular, the threshold voltages for NVM cells are compared against a threshold voltage (Vt) check voltage (V | 02-19-2015 |
20150085593 | NON-VOLATILE MEMORY (NVM) WITH DYNAMICALLY ADJUSTED REFERENCE CURRENT - A sense amplifier is configured to sense a current from a selected bit cell of a non-volatile memory array and compare the sensed current to a reference current to determine a logic state stored in the bit cell. A controller is configured to perform a program/erase operation on at least a portion of the memory array to change a logic state of at least one bit cell of the portion of the memory array; determine a number of program/erase pulses applied to the at least one bit cell during the program/erase operation to achieve the change in logic state; and when the number of program/erase pulses exceeds a pulse count threshold, adjust the reference current of the sense amplifier for a subsequent program/erase operation. | 03-26-2015 |