Scratchpad memories (SPMs) have been widely used in embedded systems to achieve comparable performance with better energy efficiency when compared to caches. Spin-transfer torque RAM (STT-RAM) is an emerging nonvolatile memory technology that has low-power and high-density advantages over SRAM. In this study we explore and evaluate a series of scratchpad memory architectures consisting of STT-RAM. The experimental results reveal that with optimized design, STT-RAM is an effective alternative to SRAM for scratchpad memory in low-power embedded systems.