Siwa: a RISC-V RV32I based Micro-Controller for Implantable Medical Applications
Ronny García-Ramírez, Alfonso Chacón-Rodríguez, Reinaldo Castro-González, Alfredo Arnaud, Matías Miguez, Joel Gak, Roberto Molina-Robles, Gabriel Madrigal-Boza, Marco Oviedo-Hernandez, E. Solera-Bolanos, Diego Salazar-Sibaja, Dayhana Sanchez-Jimenez, Melissa Fonseca-Rodriguez, Johan Arrieta-Solorzano, Renato Rímolo-Donadío
Abstract
The design of Siwa <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sup> , a compact low power custom system on chip (SoC), targeted for implantable/wearable applications, is reported in this paper. Siwa is based on a RISC-V RV32I architecture. It has a centrally controlled non-pipelined structure, and it includes a control interface for an integrated sensing and stimulation device for biological tissues as well as standard communication interfaces. Siwa was developed from scratch using System Verilog, and implemented in a 180nm CMOS technology; Siwa includes a latch based register file c apable to read and write in one clock cycle with an area 30% smaller and a power consumption 25% lower with respect to an equivalent flip flop implementation; also, it has an estimated average power consumption of 70μW (48pJ/cycle) which is comparable to other micro-controllers commonly used in IMD applications.