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Post-Silicon Debug for RISC-V Platforms: Debug Playbook

Debug Playbook for Post-Silicon Debug for RISC-V Platforms.

Debug playbook

Debug Playbook for Post-Silicon Debug for RISC-V Platforms is anchored on First-failure isolation time, reproducibility rate of silicon issues, and escaped-defect trend after debug closure.. Convert observations into mechanism-backed decisions with explicit ownership.

  1. Freeze workload seed, binary, compiler, firmware, and platform setup.

  2. Find earliest persistent mechanism failure in the timeline.

  3. Build one reduced reproducer for dominant hypothesis.

  4. Patch minimal fix with explicit rollback gate.

  5. Rerun correctness + performance + power matrix.

Decision tree

diagram
ROOT CAUSE TREE - Post-Silicon Debug for RISC-V Platforms

First-failure isolation time, reproducibility rate of silicon issues, and escaped-defect trend after debug closure. regressed
          |
   reproducible on fixed seed?
      /                 \
    no                   yes
    |                     |
env/tool drift       first failing domain?
                     /        |         \
                  decode    execute    memory/MMU
                    |         |            |
               control map  bypass/FU   TLB/walk/perm
                    |
         privilege/CSR side effects checked?

Stop at first confirmed mechanism, then assign explicit owner + fix proof.

Review memo template

diagram
RISC-V REVIEW MEMO - SoC Integration & Bring-up / Post-Silicon Debug for RISC-V Platforms

1. Symptom
   - Failing metric: First-failure isolation time, reproducibility rate of silicon issues, and escaped-defect trend after debug closure.
   - Failing workload slice: <name>
   - Triggering mode: <privilege/virtualization/interrupt/cache/boot>
   - Build and runtime tags: <toolchain/firmware/RTL revision>

2. Mechanism hypothesis
   - Primary mechanism: Post-silicon debug requires a deliberate observability strategy: trace funnels, performance counters, exception logs, and RISC-V debug-module access must be planned before tapeout. Effective teams correlate software-visible symptoms with low-level evidence such as privilege transitions, interrupt timing, and coherency-state evolution to separate firmware bugs from hardware errata. Reproduction discipline matters: each issue should have a deterministic trigger recipe, environment fingerprint, and validation of fix durability under stress. Production closure then depends on clear errata policy, mitigation ownership, and telemetry hooks that detect recurrence in field deployments.
   - Competing hypotheses: <decode control / hazard / MMU / privilege / integration>
   - Missing evidence: <trace/counter/proof/report>

3. Proposed action
   - Smallest reversible change: <RTL/compiler/runtime/config>
   - Expected movement: <throughput/latency/tail/perf-per-watt>
   - Regression risk: correctness, security, power, timing, software compatibility

4. Signoff
   - Required artifact: Silicon debug package: failure signature catalog, reproducibility playbooks, errata mitigation tracker, and field telemetry trigger definitions.
   - Required owners: post-silicon validation owner, CPU design owner, firmware debug lead, reliability engineering owner, product quality owner
   - Final decision: ship, bounded rollout, rollback, or escalate
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