Thermal-Aware Memory Mapping in 3D Designs

DRAM is usually used as main memory for program execution. The thermal behavior of a memory block in a 3D SIP is affected not only by the power behavior but also the heat dissipating ability of that block. The power behavior of a block is related to the applications run on the system, while the heat dissipating ability is determined by the number of tier and the position the block locates. Therefore, a thermal-aware memory allocator should consider the following two points. First, the allocator should consider not only the power behavior of a logic block but also the physical location during memory mapping and second, the changing temperature of a physical block during execution of programs. In this article, we will propose a memory mapping algorithm taking into consideration these two points. Our technique can be classified as static thermal management to be applied to embedded software designs. Experiments show that for single-core systems, our method can reduce the temperature of memory system by 17.1 degrees C, as compared to a straightforward mapping in the best case, and 13.3 degrees C on average. For systems with four cores, the temperature reductions are 9.9 degrees C and 11.6 degrees C on average when L1 cache of each core is set to 4KB and 8KB, respectively.