Efficient Approximate Cubing Function Circuits Based on PWL

Cubic operations are frequently used in fields such as digital signal processing and machine learning. In order to improve the efficiency of cubic unit operations, this paper proposes a novel approximation algorithm based on piecewise linear (PWL) segmentation. The approximate cubic operation unit is applied to Support Vector Machine (SVM). The SVM module is divided into an online part and an offline part. The classification accuracy of the SVM module using the approximate algorithm and the quasi-valued SVM module are 79.17% and 83.3% respectively. This paper designs a 16-bit hardware computing unit through this approximate algorithm. Compared with the previous two algorithms, the area is saved by 76% and 92% respectively, and the delay is also slightly improved. This shows that the proposed approximate algorithm can effectively improve the hardware performance under the premise of ensuring accuracy.