HMC-MAC: Processing-in Memory Architecture for Multiply-Accumulate Operations with Hybrid Memory Cube

Many studies focus on implementing processing-in memory (PIM) on the logic die of the hybrid memory cube (HMC) architecture. The multiply-accumulate (MAC) operation is heavily used in digital signal processing (DSP) systems. In this paper, a novel PIM architecture called HMC-MAC that implements the MAC operation in the HMC is proposed. The vault controllers of the conventional HMC are working independently to maximize the parallelism, and HMC-MAC is based on the conventional HMC without modifying the architecture much. Therefore, a large number of MAC operations can be processed in parallel. In HMC-MAC, the MAC operation can be carried out simultaneously with as much as 128 KB data. The correctness on HMC-MAC is verified by simulations, and its performance is better than the conventional CPU-based MAC operation when the MAC operation is consecutively executed at least six times.