Analog neural memory array storing synapsis weights in differential cell pairs in artificial neural network

A system comprising:

• an array of non-volatile memory cells, wherein the cells are arranged in rows and columns, the columns arranged in physically adjacent pairs of columns;
• wherein within each adjacent pair one column in the adjacent pair comprises cells storing W+ values and one column in the adjacent pair comprises cells storing W− values, wherein adjacent cells in the adjacent pair store a differential weight, W, according to the formula W=(W+)−(W−);
• and
• wherein the array comprises a set of columns of non-volatile memory cells utilized as a redundant array.

A system comprising:

• an array of non-volatile memory cells, wherein the cells are arranged in rows and columns, the columns arranged in physically adjacent pairs of columns;
• and
• a redundant column, wherein values stored in a W+ column or a W− column are remapped to the redundant column;
• wherein within each adjacent pair one column in the adjacent pair comprises cells storing W+ values and one column in the adjacent pair comprises cells storing W− values, wherein adjacent cells in the adjacent pair store a differential weight, W, according to the formula W=(w+)−(W−).