International Business Machines Corporation

Athanasios Vasilopoulos

Abu Sebastian

Manuel Le Gallo-Bourdeau

Julian Röttger Büchel

Benedikt J Kersting

Benedikt Kersting

The present disclosure relates to a method for compensating non-ideality of a neuromorphic memory device. The neuromorphic memory device comprising a crossbar array of wordlines and bitlines. The crossbar array comprises a block of wordline and bitline segments, wherein memory elements of the block are programmed to represent array values. The device is configured for applying a set of inputs to the initial wordlines for performing dot products. The method comprises: performing at least one of: wordline expansion or bitline expansion of the block. The set of inputs may be applied to the initial wordlines of the expanded block and in case the bitline expansion is performed an additional input may be applied to the additional wordlines of the expanded block. The currents flowing in the bitlines of the expanded block may be measured. The dot products may be determined using the measured currents.

Compensating non-ideality of a neuromorphic memory device

The invention is notably directed to a method of programming memory elements of an in-memory computing (IMC) device. The IMC applies a SET signal to the K memory elements of said each cell to set each of the K memory elements to a SET state and reading K conductance values of the K memory elements in the SET state. The IMC adjusts, based on the K conductance values read and the target conductance value, a conductance value of at least one of the K memory elements to match a summed conductance of the K memory elements of said each cell with the target conductance value. The IMC maximizes a number of the K memory elements that are either in their SET state or in a RESET state of zero conductance nominal value, such that at most one of the K memory elements is neither in a SET state nor in a RESET state.

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Rueschlikon, Switzerland

Athanasios Vasilopoulos