A low-power keyword spotting system with SRAM buffer and computing-in-memory
This paper proposes a low-power keyword spotting(KWS)system to overcome the prob-lem of high-power consumption caused by deploying KWS algorithms on edge computing hardware,which can significantly impact the endurance of mobile devices.The proposed KWS system is based on computing-in-memory(CIM)technology and software-hardware co-design.In terms of algorithm,a ternary quantized MFCC-CNN joint algorithm based on the standard MFCC algorithm topology is pro-posed.All the general matrix multiplication(GEMM)in MFCC is mapped to the neural network accel-erator.At the circuit level,the proposed system uses a computing-in-memory(CIM)core based on SRAM to overcome the power and memory walls in traditional von Neumann architecture accelerators.Additionally,a SRAM buffer circuit based on a look-up table is proposed to replace the register delay chain,which multiplexes the memory array in the CIM core.Both the SRAM-based CIM core and buffer are implemented using custom circuit units.At the system level,a low-power KWS system is proposed utilizing the two customized circuits discussed above.The system is implemented using ASIC and cus-tomized circuit design methods and synthesized using a 28 nm process library.The proposed system achieves a processing delay of 64 ms on 10 classification tasks,with a total power consumption of 645.28μW.The dynamic power consumption of the MFCC pipeline accounts for 5.9%of the total dynamic power consumption,and the total power consumption accounts for only 1.3%of the system's power consumption.
spottingternary quantized neural networkcomputing-in-memoryserial fast Fourier transform(FFT)software-hardware co-design