Efficient Data Extraction Circuit for Posit Number System: LDD-Based Posit Decoder
Jianchi Sun, Yingjie Lao
Abstract
Since being proposed in 2017, the posit number system has attracted much attention due to its advantages over the IEEE 754 standard floating-point format for better dynamic range and higher accuracy, which are crucial to many applications such as neural networks. Those advantages are yielded from a varying-length segment, regime bits, which lead to the size variations for all rest components except the sign bit. Consequently, it requires an extra decoding process to extract the numerical value of a posit number. The state-of-the-art posit decoder is designed based on a leading one/zero detector. However, we find that this conventional method holds implicit redundancy when dealing with binary numbers. In this paper, we design a novel hardware architecture, i.e., the leading difference detector, to optimize the circuit operation by eliminating the redundancy. The experimental results show that the proposed architecture can decrease the delay and power consumption by over 41% compared to the conventional designs for 8-bit, 16-bit, 32-bit, and 64-bit posit decoders.