FPUx: High-Performance Floating-Point Support for Cost-Constrained RISC-V Cores

In the Internet of Things (IoT) field, cloud and fog computing dramatically increase the complexity of floating-point (FP) calculations. Cost-constrained microcontrollers (MCUs) urgently need more efficient FP computing methods, such as integrated FP units (FPUs). To this end, this brief proposes FPUx, a high-performance FPU designed through a hybrid pipeline and state-machine approach. The FPUx is integrated into E203 for implementation (E203-FPUx). Furthermore, the Easy-lite is proposed to reduce handshake delay and a range of single-precision FP (FP32) arithmetic IPs are designed to customize FPUs. Compared with E203-FPnew and E203, the performance of E203-FPUx is improved by 1.5
$\times$
and 36
$\times$
, and the total energy consumption is saved by 36% and 1430% on average, respectively.