Multiple-state digital computing based on memory technologies. (a) Schematic of decimal summation operation with an accumulative PCM. (b) Factorization of a number with the parallel PCM devices. (c) Flow process of temporal correlation detection achieved by accumulative PCM devices. (d) Experimental demonstration of 1000 × 1000 PCM devices to map the correlated processes. Panels (c) and (d) are reproduced from Ref. [148].