An integrated circuit (IC) device may include a first portion having a plurality of volatile memory cells; and a second portion coupled by a data transfer path to the first portion, the second portion including a plurality of nonvolatile memory cells, each nonvolatile memory cell including at least one resistive element programmable more than once between different resistance values. A memory device may also include variable impedance elements accessible by access bipolar junction transistors (BJTs) having at least a portion formed by a semiconductor layer formed over a substrate. A memory device may also include a plurality of memory elements that each includes a dielectric layer formed between a first and second electrode, the dielectric layer including a solid electrolyte with a soluble metal having a mobility less than that of silver in a germanium disulfide.