ARC Members

Open Krste Asanović Chair Unpriv IC krste@sifive.com SiFive	Open Earl Killian Vice-Chair Unpriv IC earl.killian@arilinc.com Aril Inc.

Definition of Architecture Review (AR)

AR is a structured process to ensure robust, consistent RISC-V architecture extensions align with ratified specifications and the overall RISC-V strategy. It involves reviewing architectural consistency, cost/benefit justifications, and adherence to RISC-V standards. See the AR Policy for more details.

Goals of AR

• Produce consistent and high-quality architecture extensions.

• Coordinate opcode, mnemonic, and CSR assignments.

• Ensure responsiveness and thoroughness in reviews.

• Maintain architectural consistency across extensions and profiles.

Communication Channels

• tech-arch-review@lists.riscv.org: primary portal for submitting architecture extensions or key issues for review.https://lists.riscv.org/g/tech-arch-review

• Privileged Spec (IC) mailing list: https://lists.riscv.org/g/tech-privileged

• Unprivileged Spec (IC) mailing list: https://lists.riscv.org/g/tech-unprivileged

Key AR Activities

1. Architecture Reviews:

   • Conducted by the Unprivileged and Privileged ISA Committees (ICs).

   • Reviews ensure extensions are suitable for RISC-V standardization, focusing on architectural integrity and justification.

2. Opcode Assignment Reviews:

   • Managed dynamically by IC chairs and their delegates.

3. CSR Assignment Reviews:

   • Delegated to knowledgeable individuals for thorough evaluation.

4. Definition of Done (DoD) Sign-offs:

   • Includes early opcode assignments and other deliverables as part of extension readiness milestones.

AR in the Specification Development Lifecycle

• Planning/Development: Consultative role, offering guidance on architectural choices.

• Freeze Stage: Mandatory review to ensure readiness for specification advancement.

• Ratification-Ready Stage: Required if substantial changes have occurred in the specification.