-
公开(公告)号:US20210326110A1
公开(公告)日:2021-10-21
申请号:US16850395
申请日:2020-04-16
Applicant: SanDisk Technologies LLC
Inventor: Wen Ma , Pi-Feng Chiu , Won Ho Choi , Martin Lueker-Boden
Abstract: Technology for reconfigurable input precision in-memory computing is disclosed herein. Reconfigurable input precision allows the bit resolution of input data to be changed to meet the requirements of in-memory computing operations. Voltage sources (that may include DACs) provide voltages that represent input data to memory cell nodes. The resolution of the voltage sources may be reconfigured to change the precision of the input data. In one parallel mode, the number of DACs in a DAC node is used to configure the resolution. In one serial mode, the number of cycles over which a DAC provides voltages is used to configure the resolution. The memory system may include relatively low resolution voltage sources, which avoids the need to have complex high resolution voltage sources (e.g., high resolution DACs). Lower resolution voltage sources can take up less area and/or use less power than higher resolution voltage sources.
-
公开(公告)号:US20210110235A1
公开(公告)日:2021-04-15
申请号:US16653346
申请日:2019-10-15
Applicant: SanDisk Technologies LLC
Inventor: Tung Thanh Hoang , Won Ho Choi , Martin Lueker-Boden
Abstract: Techniques are presented for accelerating in-memory matrix multiplication operations for a convolution neural network (CNN) inference in which the weights of a filter are stored in the memory of a storage class memory device, such as a ReRAM or phase change memory based device. To improve performance for inference operations when filters exhibit sparsity, a zero column index and a zero row index are introduced to account for columns and rows having all zero weight values. These indices can be saved in a register on the memory device and when performing a column/row oriented matrix multiplication, if the zero row/column index indicates that the column/row contains all zero weights, the access of the corresponding bit/word line is skipped as the result will be zero regardless of the input.
-
公开(公告)号:US10886458B2
公开(公告)日:2021-01-05
申请号:US16449876
申请日:2019-06-24
Applicant: SanDisk Technologies LLC
Inventor: Young-Suk Choi , Won Ho Choi
Abstract: Apparatuses, systems, and methods are disclosed for magnetoresistive random access memory. A magnetic tunnel junction for storing data may include a reference layer, a barrier layer, and a free layer. A barrier layer may be disposed between a reference layer and a free layer. A free layer may include a nucleation region and an arm. A nucleation region may be configured to form a magnetic domain wall. An arm may be narrower than a nucleation region and may extend from the nucleation region. An arm may include a plurality of pinning sites formed at predetermined locations along the arm for pinning a domain wall.
-
公开(公告)号:US20200311512A1
公开(公告)日:2020-10-01
申请号:US16901302
申请日:2020-06-15
Applicant: SanDisk Technologies LLC
Inventor: Won Ho Choi , Pi-Feng Chiu , Wen Ma , Minghai Qin , Gerrit Jan Hemink , Martin Lueker-Boden
Abstract: Use of a NAND array architecture to realize a binary neural network (BNN) allows for matrix multiplication and accumulation to be performed within the memory array. A unit synapse for storing a weight of a BNN is stored in a pair of series connected memory cells. A binary input is applied as a pattern of voltage values on a pair of word lines connected to the unit synapse to perform the multiplication of the input with the weight by determining whether or not the unit synapse conducts. The results of such multiplications are determined by a sense amplifier, with the results accumulated by a counter.
-
公开(公告)号:US10732933B2
公开(公告)日:2020-08-04
申请号:US15976384
申请日:2018-05-10
Applicant: SanDisk Technologies LLC
Inventor: Won Ho Choi
Abstract: True random number generation (TRNG) circuits are presented which employ magnetic tunnel junction (MTJ) elements that can change magnetization state probabilistically in response to application of electrical pulses. Some implementations include pulse generators which apply perturbation sequences to the MTJ elements. The MTJ elements responsively produce randomized outputs related to changes in magnetization states. Probability compensators are included which monitor for deviations in measured probabilities in the randomized outputs from a target probability. The probability compensators make adjustments to the perturbation sequences to influence probabilistic changes in the magnetization states of the MTJ elements and bring the measured probabilities to within a predetermined deviation from the target probability.
-
公开(公告)号:US10374148B1
公开(公告)日:2019-08-06
申请号:US15959837
申请日:2018-04-23
Applicant: SanDisk Technologies LLC
Inventor: Young-Suk Choi , Won Ho Choi
CPC classification number: H01L43/02 , G06N3/04 , G06N3/063 , G11C11/161 , G11C11/1675 , H01L27/222 , H01L43/08
Abstract: Apparatuses, systems, and methods are disclosed for magnetoresistive random access memory. A magnetic tunnel junction (MTJ) for storing data may include a reference layer. A free layer of an MTJ may be separated from a reference layer by a barrier layer. A free layer may be configured such that one or more resistance states for an MTJ correspond to one or more positions of a magnetic domain wall within the free layer. A domain stabilization layer may be coupled to a portion of a free layer, and may be configured to prevent migration of a domain wall into the portion of the free layer.
-
公开(公告)号:US11521658B2
公开(公告)日:2022-12-06
申请号:US16460947
申请日:2019-07-02
Applicant: SanDisk Technologies LLC
Inventor: Won Ho Choi , Pi-Feng Chiu , Martin Lueker-Boden
IPC: G11C5/14 , G11C13/00 , G11C11/22 , G06F17/16 , G11C11/16 , G11C5/06 , G06N3/08 , G06N3/063 , G06N3/04
Abstract: An illustrative embodiment disclosed herein is an apparatus including a non-volatile memory cell and multi-bit input circuitry that simultaneously receives a plurality of bits, receives a supply voltage, converts the plurality of bits and the supply voltage into a multiply voltage, and applies the multiply voltage to the non-volatile memory cell. The non-volatile memory cell may pass a memory cell current in response to the multiply voltage. A magnitude of the multiply voltage may represent a multiplier. The memory cell current may represent a product of the multiplier and a multiplicand stored in the non-volatile memory cell.
-
公开(公告)号:US20210192325A1
公开(公告)日:2021-06-24
申请号:US16722580
申请日:2019-12-20
Applicant: SanDisk Technologies LLC
Inventor: Tung Thanh Hoang , Won Ho Choi , Martin Lueker-Boden
Abstract: Techniques are presented for performing in-memory matrix multiplication operations for binary input, binary weight valued convolution neural network (CNN) inferencing. The weights of a filter are stored in pairs of memory cells of a storage class memory device, such as a ReRAM or phase change memory based devices. To reduce current consumption, the binary valued filters are transformed into ternary valued filters by taking sums and differences of binary valued filter pairs. The zero valued weights of the transformed filters are stored as a pair of high resistance state memory cells, reducing current consumption during convolution. The results of the in-memory multiplications are pair-wise combined to compensate for the filter transformations. To compensate for zero valued weights, a zero weight register stores the number of zero weights along each bit line and is used to initialize counter values for accumulating the multiplication operations.
-
公开(公告)号:US20210117499A1
公开(公告)日:2021-04-22
申请号:US16655575
申请日:2019-10-17
Applicant: SanDisk Technologies LLC
Inventor: Minghai Qin , Pi-Feng Chiu , Wen Ma , Won Ho Choi
Abstract: Systems and methods for reducing the impact of defects within a crossbar memory array when performing multiplication operations in which multiple control lines are concurrently selected are described. A group of memory cells within the crossbar memory array may be controlled by a local word line that is controlled by a local word line gating unit that may be configured to prevent the local word line from being biased to a selected word line voltage during an operation; the local word line may instead be set to a disabling voltage during the operation such that the memory cell currents through the group of memory cells are eliminated. If a defect has caused a short within one of the memory cells of the group of memory cells, then the local word line gating unit may be programmed to hold the local word line at the disabling voltage during multiplication operations.
-
公开(公告)号:US20200034697A1
公开(公告)日:2020-01-30
申请号:US16368347
申请日:2019-03-28
Applicant: SanDisk Technologies LLC
Inventor: Won Ho Choi , Pi-Feng Chiu , Wen Ma , Minghai Qin , Gerrit Jan Hemink , Martin Lueker-Boden
Abstract: Use of a NAND array architecture to realize a binary neural network (BNN) allows for matrix multiplication and accumulation to be performed within the memory array. A unit synapse for storing a weight of a BNN is stored in a pair of series connected memory cells. A binary input is applied as a pattern of voltage values on a pair of word lines connected to the unit synapse to perform the multiplication of the input with the weight by determining whether or not the unit synapse conducts. The results of such multiplications are determined by a sense amplifier, with the results accumulated by a counter.
-
-
-
-
-
-
-
-
-