Memristive arrays with offset elements
AssigneeHewlett Packard Enterprise Development LP
InventorsBrent Buchanan, Le Zheng, John Paul Strachan
Life of this patent
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Abstract
In one example in accordance with the present disclosure a device is described. The device includes a cross-bar array of memristive elements. Each memristive element has a conductance value. The device also includes a column of offset elements. An offset element is coupled to a row of memristive elements and has a conductance value. The device also includes a number of accumulation elements. An accumulation element is coupled to a column of memristive elements. The accumulation element collects an intermediate output from the column and subtracts from the intermediate output an output from the column of offset elements.
Claims20
An apparatus, comprising:
- a plurality of memristive elements, wherein a respective memristive element has a conductance value that indicates an input value;
- a column of offset elements, wherein a respective offset element is coupled to a row of memristive elements of the plurality of memristive elements and has a conductance value that indicates an offset value for adding to the input value;
- and
- a plurality of accumulation elements, wherein a respective accumulation element is coupled to a column of memristive elements of the plurality of memristive elements and the column of offset elements;
- wherein the accumulation element is configured to:
- collect an intermediate output from the column of memristive elements;
- and
- subtract from the intermediate output an output from the column of offset elements.
A method for computing a dot product comprising:
- applying voltages to a plurality of row lines in a crossbar array,
- wherein a respective voltage defines an input value of an input vector, and
- wherein a respective row line comprises:
- a plurality of memristive elements;
- and
- an offset element, which has a conductance value that indicates an offset value for adding to the input value;
- collecting, for respective column of memristive elements in the crossbar array, an intermediate output that indicates a dot product of the input vector and an offset weight vector of an offset weight matrix wherein the offset weight vector includes a set of weight values from an original matrix that have been offset by the offset value;
- collecting, for a column of offset elements, an offset output that indicates a dot product of the input vector and an offset vector of the offset value;
- and
- subtracting the offset output from a respective intermediate output to generate a column output that indicates a dot product of the input vector and a weight vector.
A crossbar array comprising:
- a plurality of row lines to pass voltages indicating input values of an input vector to rows of memristive elements;
- a plurality of column lines intersecting the row lines to form a number of junctions;
- a plurality of memristive elements coupled between the row lines and the column lines at the junctions, wherein a respective memristive element has a conductance value that indicates one of the input values;
- an offset element column, wherein a respective offset element is coupled to a row of memristive elements and has a conductance value that indicates an offset value for adding to the input value;
- an offset column line configured to collect an offset output of the offset element column;
- a plurality of memristive column lines, wherein a respective memristive column line is configured to collect an intermediate output of a corresponding column of memristive elements;
- and
- a plurality of accumulation elements, wherein a respective accumulation element is coupled to a column of memristive elements and configured to subtract the offset output from a respective intermediate output.
Dependencies are inferred from the claim text.