SMURF

Abstract

This paper proposes an innovative Floating Point (FP) architecture for Variable Precision (VP) computation suitable for high precision FP computing, based on a refined version of the UNUM type I format. This architecture supports VP FP intervals where each interval endpoint can have up to 512 bits of mantissa. The proposed hardware architecture is pipelined and has an internal word-size of 64 bits. Computations on longer mantissas are performed iteratively on the existing hardware. The prototype is integrated in a RISC-V environment, it is exposed to the user through an instruction set extension. The paper we provide an example of software usage. The system has been prototyped on a FPGA (Field-Programmable Gate Array) platform and also synthesized for a 28nm FDSOI process technology. The respective working frequency of FPGA and ASIC implementations are 50MHz and 600MHz. The estimated chip area is 1.5mm2 and the estimated power consumption is 95mW. The flops performance of this architecture remains within the range of a regular fixed-precision IEEE FPU while enabling arbitrary precision computation at reasonable cost.