Next generation non-volatile memory technologies draw attention recently as promising candidates for replacing conventional DRAM-based memory devices. By using the favorable features such as low energy consumption, non-volatility, and good scalability, the next generation non-volatile memory devices can replace conventional main memory and secondary storage layers. This paper proposes a hot-cold data filtering adapter with it management algorithm for the memory-storage unified system which uses phase change RAM (PRAM) devices. The proposed hot-cold data filtering adapter consisting of dual decoupled adaptive buffers can improve drawbacks of PRAM, such as slower read/write access latencies and limited life time compared to DRAM, enhance spatial/temporal localities, and optimize the data reusability by analyzing data access pattern. Experimental results show that the proposed architecture and its algorithm improves the miss rate by about 69.2% and write count is decreased by 96.4% compared with a uniform buffer of the same size.