Extensive work has been done for optimal management of scratch-pad memory (SPM) all assuming that the SPM is assigned a fixed address space. The main target objects to be placed on the SPM have been code and global memory since their sizes and locations are not changed dynamically. We propose a novel idea of dynamic address mapping of SPM with the assistance of memory management unit (MMU). It allows us to use SPM for stack management without architecture modification and complier assistance. The proposed technique is orthogonal to the previous works so can be used at the same time. Experiments results show that the proposed technique results in average performance improvement of 13% and energy savings of 12% observed compared to using only external DRAM. And it also gives noticeable speed up and energy saving against a typical cache solution for stack data.