October 2025 monthly summary for OpenXiangShan-Nanhu/LinkNan focusing on delivering robust PLDM tooling, improved simulation fidelity, and build/memory modeling enhancements to accelerate bring-up, validation, and debug workflows.

Month: 2025-09. This monthly summary highlights key features delivered, major bugs fixed, overall impact, and technologies demonstrated in the OpenXiangShan-Nanhu/LinkNan repository work during September 2025, focusing on business value and technical achievement.

In August 2025, I focused on stabilizing and enhancing the LinkNan testing infrastructure for OpenXiangShan-Nanhu/LinkNan. The month delivered targeted dependency management and test-environment improvements that directly support faster, more reliable verification of changes in the CPU/GPU verification stack. Key deliverables include: - Dependency updates for Difftest and Nemus: consolidated updates for testing subprojects, upgrading Difftest to commit bac2c08 (from a710be1) and aligning submodule references; updated NemU version in the ready-to-run configuration. Associated commits: b1a055506fbbf84a8f93c4862d4088655046cc2a, d90892bed7a97c7357fad5a70e1be813b85e24d2, df5c4ecc0231ce9966b4fa58c1bfe625f8c509a7. - Increased simulated memory for testing: raised simMemory from 8GB to 16GB by updating configuration and the dummy DRAM module to support larger test workloads. Commit: 07aecbb36691820ff35da4d338b353d1b1a9ccdf. Major bugs fixed/infra improvements: - Corrected and stabilized the test environment by removing drift in dependencies and enabling higher-memory test scenarios, improving test determinism and coverage. Overall impact and accomplishments: - Faster, more reliable testing cycles with larger workload capacity; reduced maintenance burden due to consolidated dependency management; clearer submodule alignment across testing projects. Technologies/skills demonstrated: - Dependency management and version pinning, submodule coordination, test infra configuration, and environment stabilization.

July 2025 monthly summary focused on delivering core testing infrastructure enhancements, stabilizing the Difftest workflow, and optimizing resource usage across Nanhu-V5 and LinkNan. The work emphasizes business value through more reliable tests, faster feedback, and lower infra costs, while demonstrating strong cross-repo collaboration and modern build/dependency practices.

June 2025 monthly summary for OpenXiangShan-Nanhu/Nanhu-V5 focusing on verification hardening and maintainability through SystemVerilog Assertions and RegCache improvements. Key work centered on adding toggleable SVA-based verification for BusyTable and strengthening RegCache validation, with readability improvements to assertion logic to reduce maintenance burden. Impact: Increased confidence in BusyTable state transitions and RegCache wakeup behavior; verification overhead remains controllable via feature flags, preserving performance while catching subtle bugs earlier in the development cycle. Tech emphasis: SystemVerilog Assertions (SVA), Verilog/SystemVerilog verification practices, Scala-based assertions readability improvements, and general verification engineering.

May 2025 (2025-05) monthly summary for Nanhu-V5. This period delivered substantial architectural refinements, verification improvements, and dependency updates that collectively improved stability, timing accuracy, and maintainability across the OpenXiangShan-Nanhu/Nanhu-V5 repo.

April 2025 monthly summary for OpenXiangShan-Nanhu/Nanhu-V5: Delivered key features in vector unit performance, verification tooling, and memory robustness while fixing critical decoder correctness issues and enabling prefetch control. Strengthened business value by boosting throughput, reducing decoding-related risk, enhancing fault detection, and enabling modular AIA-based asynchronous interrupt support. Demonstrated proficiency in RTL timing optimization, assertion-based verification, and prefetch control integration.

Month: 2025-03 — Nanhu-V5: Focused on reliability improvements in FP and CSR paths. Implemented targeted fixes to FP instruction handling and CSR exception handling. No new features delivered this month; improvements center on correctness and stability in critical instruction paths, enabling safer production runs and easier debugging.

February 2025 (2025-02) — Nanhu-V5 monthly summary: Achievements span FP/Vector pipeline stabilization, refactor consolidation, and build reliability improvements. Key outcomes include removing the fcvt module and unifying FP conversion path for simpler decoding/execution, stabilizing vector instruction handling and VF IQ signaling, restoring stable register file behavior after a refactor, tuning VF IQ capacity for better timing, and hardening the build system to reference project-root paths. These changes improved correctness, reduced stalls, and boosted throughput while reducing maintenance risk.

January 2025 (2025-01) focused on delivering vector engine enhancements, refactoring for reliability and maintainability, and a broad set of bug fixes to stabilize the VF path in OpenXiangShan-Nanhu/Nanhu-V5. Key capabilities added include IssueQueue-based dispatch with shared VF/RF ports, and active element selection support in VFALU64/VFMA64. The work also included IQ-driven control refinements, regfile modernization, and data-path improvements, together with widespread bug fixes across writeback, data forwarding, and instruction flow. These changes improve vector throughput, correctness, and developer productivity, enabling more reliable SIMD workloads and faster iteration cycles for future features.

December 2024 focused on delivering a revamped Vector Unit path in OpenXiangShan-Nanhu/Nanhu-V5, consolidating FP scheduling into the vector pipeline, enabling 64-bit FP and 128-bit vector operations, and enhancing wake-up and debugging capabilities. The work also covered correctness and stability fixes to FP and vector paths, and targeted maintainability improvements in the DataPath via a separated diplomacy library.