Basilisk: A 34 mm2 End-to-End Open-Source 64-bit Linux-Capable RISC-V SoC in 130nm BiCMOS

TL;DR

Basilisk is the largest open-source end-to-end RISC-V SoC implemented in 130nm BiCMOS, demonstrating significant improvements in design flow, size, and performance for Linux-capable chips.

Contribution

This work presents Basilisk, the largest open-source RISC-V SoC in 130nm BiCMOS, with enhanced design flow and verified performance, enabling large, industry-grade open-source chips.

Findings

Successfully fabricated Basilisk chip reaching 62 MHz at 1.2 V

Achieved 102 MHz at 1.64 V with the chip

Peak energy efficiency of 18.9 DP MFLOP/s/W at 0.88 V

Abstract

End-to-end open-source electronic design automation (OSEDA) enables a collaborative approach to chip design conducive to supply chain diversification and zero-trust step-by-step design verification. However, existing end-to-end OSEDA flows have mostly been demonstrated on small designs and have not yet enabled large, industry-grade chips such as Linux-capable systems-on-chip (SoCs). This work presents Basilisk, the largest end-to-end open-source SoC to date. Basilisk's 34 mm2, 2.7 MGE design features a 64-bit Linux-capable RISC-V core, a lightweight 124 MB/s DRAM controller, and extensive IO, including a USB 1.1 host, a video output, and a fully digital 62 Mb/s chip-to-chip (C2C) link. We implement Basilisk in IHP's open 130 nm BiCMOS technology, significantly improving on the state-of-the-art (SoA) OSEDA flow. Our enhancements of the Yosys-based synthesis flow improve design timing and area by 2.3x and 1.6x, respectively, while consuming significantly less system resources. By tuning OpenROAD place and route (P&R) to our design and technology, we decrease the die size by 12%. The fabricated Basilisk chip reaches 62 MHz at its nominal 1.2 V core voltage and up to 102 MHz at 1.64 V. It achieves a peak energy efficiency of 18.9 DP MFLOP/s/W at 0.88 V.