A Fully Programmable eFPGA-Augmented SoC for Smart-Power Applications

This paper proposes a reconfigurable System-on-Chip (SoC) for Smart-Power applications. The system is composed of an ultra-low-power microcontroller for standard software programmability, coupled to an embedded-FPGA (eFPGA) to perform control-driven applications, featuring digital elaboration with small computational load, at a lower power consumption and higher responsiveness compared to processor-based implementation. Added value of the proposed system is that the whole digital system is synthesizable, since also the eFPGA is based on a soft-core approach. In the paper we discuss the application domain and present the results of integrating an eFPGA with a computational capability of ≈1K equivalent gates in the STMicroelectronics $0.13\ \boldsymbol{\mu} \mathbf{m}$ Bipolar, CMOS, DMOS (BCD) Smart-Power technology featuring only four metal layers. As expected, eFPGA integration in the SoCs introduces a significant area-overhead (about $20\div25\%$ ), but has a straightforward benefit in terms of energy consumption reduction compared to processor-based implementations. On average, based on our analysis, the energy gain achievable in this scenario can be quantified in a couple of orders of magnitude.