Patent classifications
G11C2029/5002
MEMORY ARRAY TEST METHOD AND SYSTEM
A method of testing a non-volatile memory (NVM) array includes obtaining a current distribution of a subset of NVM cells of the NVM array, the current distribution including first and second portions corresponding to respective logically high and low states of the subset of NVM cells, programming an entirety of the NVM cells of the NVM array to one of the logically high or low states, determining an initial bit error rate (BER) by performing first and second pass/fail (P/F) tests on each NVM cell of the NVM array, and using the current distribution to adjust the initial BER rate. Each of obtaining the current distribution, programming the entirety of the NVM cells, and performing the first and second P/F tests is performed while the NVM array is heated to a target temperature.
Two way single VREF trim for fully differential CDAC for accurate temperature sensing
A temperature sensing circuit of a data storage system includes a temperature sensor, a digital-to-analog circuit, and a reference generation and trimming circuit configured to generate a common mode voltage (VCM), a positive reference voltage (VREFP), and a negative reference voltage (VREFN) using a single band gap reference signal. The trimming circuit is configured to trim the VCM, VREFP, and VREFN by adjusting a VC trim signal to increase the VCM until a VCM error is below a threshold; adjusting a high temperature trim signal to increase the VREFP and decrease the VREFN until a digital temperature signal associated with the digital-to-analog circuit attains a predetermined accuracy level for a first temperature; and adjusting a low temperature trim signal to increase the VREFP, VCM, and VREFN until the digital temperature signal attains a predetermined accuracy level for a second temperature.
Secure chip identification using resistive processing unit as a physically unclonable function
A technique relates to biasing, using a control system, a crossbar array of resistive processing units (RPUs) under a midrange condition, the midrange condition causing resistances of the RPUs to result in a random output of low values and high values in about equal proportions. The control system reinforces the low values and the high values of the random output by setting the resistances of the RPUs to a state that forces the low values and the high values having resulted from the midrange condition. Reinforcing the low values and the high values makes the random output permanent even when the crossbar array of the RPUs is not biased under the midrange condition. The control system records a sequence of the low values and the high values of the random output responsive to reinforcing the low values and the high values of the random output.
Method and apparatus for PUF generator characterization
Disclosed is a physical unclonable function generator circuit and testing method. In one embodiment, a testing method for physical unclonable function (PUF) generator includes: verifying a functionality of a PUF generator by writing preconfigured logical states to and reading output logical states from a plurality of bit cells in a PUF cell array; determining a first number of first bit cells in the PUF cell array, wherein the output logical states of the first bit cells are different from the preconfigured logical states; when the first number of first bit cells is less than a first predetermined number, generating a first map under a first set of operation conditions using the PUF generator and a masking circuit, generating a second map under a second set of operation conditions using the PUF generator and the masking circuit, determining a second number of second bit cells, wherein the second bit cells are stable in the first map and unstable in the second map; when the second number of second bit cells is determined to be zero, determining a third number of third bit cells, wherein the third bit cells are stable in the first map and stable in the second map; and when the third number of third bit cells are greater than a second preconfigured number, the PUF generator is determined as a qualified PUF generator.
Method of Determining Defective Die Containing Non-volatile Memory Cells
A method of testing non-volatile memory cells formed on a die includes erasing the memory cells and performing a first read operation to determine a lowest read current RC1 for the memory cells and a first number N1 of the memory cells having the lowest read current RC1. A second read operation is performed to determine a second number N2 of the memory cells having a read current not exceeding a target read current RC2. The target read current RC2 is equal to the lowest read current RC1 plus a predetermined current value. The die is determined to be acceptable if the second number N2 is determined to exceed the first number N1 plus a predetermined number. The die is determined to be defective if the second number N2 is determined not to exceed the first number N1 plus the predetermined number.
Memory apparatus and method of operation using periodic normal erase dummy cycle to improve stripe erase endurance and data retention
A memory apparatus and method of operation are provided. The apparatus includes memory cells connected to one of a plurality of word lines and arranged in strings and configured to retain a threshold voltage corresponding to one of a plurality of memory states. A control circuit is coupled to the plurality of word lines and strings and is configured to erase the memory cells using a stripe erase operation in response to determining a cycle count is less than a predetermined cycle count maximum threshold. The control circuit is also configured to perform a dummy cycle operation in response to determining the cycle count is not less than the predetermined cycle count maximum threshold.
STORAGE DEVICES AND METHODS OF OPERATING STORAGE DEVICES
Example embodiments provide for a storage device that includes a storage controller including a plurality of analog circuits and at least one nonvolatile memory device including a first region and a second region. The at least one nonvolatile memory device stores user data in the second region and stores trimming control codes in the first region as a compensation data set. The trimming control codes are configured to compensate for offsets of the plurality of analog circuits and are obtained through a wafer-level test on the storage controller. The storage controller, during a power-up sequence, reads the compensation data set from the first region of the at least one nonvolatile memory device, stores the read compensation data set therein, and adjusts the offsets of the plurality of analog circuits based on the stored compensation data set.
SEMICONDUCTOR CHIP, METHOD OF FABRICATING THEREOF, AND METHOD OF TESTING A PLURALITY OF SEMICONDUCTOR CHIPS
A semiconductor chip may include a memory, a power supply line, a noise generator and a switch. The power supply line may include first and second power supply line portions. The power supply line may be configured to provide a power supply signal through each of the first power supply line portion and the second power supply line portion. The noise generator may be connected to the second power supply line portion. The noise generator may be configured to receive the power supply signal from the second power supply line portion, and output a noisy power supply signal based on the power supply signal. The switch may be coupled to the memory, the first power supply line portion, and the noise generator. The switch may be configured to selectively electrically connect the memory to one of the first power supply line portion and the noise generator.
AUTO-POWER ON MODE FOR BIASED TESTING OF A POWER MANAGEMENT INTEGRATED CIRCUIT (PMIC)
Methods, systems, and devices supporting an auto-power on mode for biased testing of a power management integrated circuit (PMIC) are described. A system may program a PMIC of a memory system to a specific mode. The mode may cause the PMIC to apply a bias to a memory device of the memory system upon receiving power and independent of a command to apply the bias to the memory device. The system may transmit power to the memory system while controlling one or more operating conditions (e.g., temperature, humidity) for a threshold time. The PMIC may apply a bias to the memory device during the threshold time based on the PMIC being programmed to the mode and the transmitted power. The system may identify a capability or defect of the memory device resulting from transmitting the power to the memory system while controlling the operating conditions for the threshold time.
OPTIMIZING MEMORY ACCESS OPERATION PARAMETERS
A corresponding value of a data state metric associated with each of a value of a plurality of values of a memory access operation parameter used in one or more memory access operation is measured. An optimal metric value based on the measured values of the predetermined data state metric is determined. An optimal value of the memory access operation parameter from the plurality of values of the memory access operation parameter is selected.