A fusion memory device having phase change memory devices that have different resistance distributions and a corresponding data processing system is presented. The fusion memory device includes a first and a second phase change memory group arranged on the same chip. Because the second phase change memory group exhibits a resistance distribution different from that of the first phase change memory group, then the fusion memory device can be configured to simultaneously function as both a DRAM device and as a flash memory device. Because the first and second phase change memory groups can be composed of similar PRAM components, the corresponding manufacturing and driving circuitry is markedly simplified as compared to other fusion memory devices that have dissimilar DRAM and flash memory components.