In the architecture of system-on-chip (SoC) design, the bus plays a critical role by facilitating inter-module connections and managing data transmission. Although the commercial bus solutions represented by the Cortex-M System Design Kit (CMSDK) are widely adopted in the industry, they exhibit lower communication efficiency in certain specialized requirements. This research focuses on optimizing the transition from a 32-bit high-speed intra-core bus to a 64-bit low-speed AHB-Lite bus. A new solution (MergFS) for this conversion process is proposed and implemented, which supports request merging and dynamic frequency switching. Experimental results show that, compared to the solution using CMSDK, MergFS reduces clock cycles by approximately 50% to 75% when processing multiple transactions. Additionally, synthesis results under the three different technologies show MergFS introduces ~4.5% area and ~6.02% power overhead on average.

The RISC-V architecture is increasingly deployed in safety-critical domains, such as automotive systems, yet the register file remains susceptible to Single Event Upsets (SEUs). Traditional fault-tolerance schemes like Triple Modular Redundancy (TMR) and Error Correction Codes (ECC) incur excessive area overhead (>200%) or significant performance penalties (15.3–20.5% timing degradation), and critically, cannot prevent error accumulation. To address this, we propose I-COR , an instruction-level correction scheme that targets register file data errors. When an instruction accesses a corrupted register, I-COR replaces it with a corrective instruction pair: the first instruction rectifies the erroneous value through the write-back path to prevent error accumulation, while the second re-executes the original operation. By reusing existing forwarding paths, this pair maintains pipeline efficiency, introducing just one-cycle correction latency. Implemented on the Ibex core and synthesized in 28 nm, 110 nm CMOS, and 180 nm SOI technologies, I-COR reduces area overhead by 50.92–62.83% compared to TMR while avoiding ECC’s timing degradation. Our automated two-stage fault-injection validation demonstrates I-COR’s effectiveness: it achieves complete elimination of critical faults (0% occurrence for both application output mismatches and system hangs) and reduces non-critical faults (internal architectural errors without system-level impact) down to 0.12–3.17%, outperforming existing schemes by 2.6–28.8×. By combining minimal area, zero timing penalty, single-cycle correction latency, and guaranteed prevention of error accumulation, I-COR provides an efficient architectural-level fault-tolerance solution specifically designed for register file protection in safety-critical three-stage pipeline RISC-V processors.

Current processor chip designs are mainly oriented by performance, power and area (PPA), and developed using the waterfall model. However, there are two main challenges in this development model: 1) The end-to-end iteration cycle and cost of processor chip development are too high, and cannot flexibly respond to changes in chip fragmented design specifications. 2) Processor chip verification is less agile, and there is a lack of a full-chain processor agile design platform that can be easily ported to different development environments. To tackle both issues, we propose an object-oriented hardware agile design methodology, oriented by time, cost, and complexity, and have built the RIVL platform to support the agile development process for processors. RIVL integrates a highly automated design flow for processor RTL design, Integration, Verification, and Layout design to improve processor development efficiency. We achieved tape-out verification of more than 60 RISC-V processors through agile design methods, demonstrating the use and effectiveness of RIVL. We quantify the performance of CoreGen using CoreMark and demonstrate that CoreGen achieves industry-competitive performance.