A device comprises a first block of memory cells, a second block of memory cells to store a feature array, and a third block of memory cells to store an array of output values. Sensing circuitry is coupled to the first block of memory cells and the second block of memory cells to compare electrical differences between the memory cells in the first block and the memory cells in the second block to generate the array of output values. Writing circuitry is operatively coupled to the third block to store the array of output values in the third block of memory cells.