菜单
Delay/traffic randomization in RDS-DV - the 19 named FlexConfigGen profiles, which layer to use, and the rule that randomized traffic does NOT prove fairness or arbitration correctness. Use when shaping stimulus timing, writing an arbiter/scheduler/picker test, or choosing a delay profile.
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基于 SOC 职业分类
| name | rds-dv-randomization |
| description | Delay/traffic randomization in RDS-DV - the 19 named FlexConfigGen profiles, which layer to use, and the rule that randomized traffic does NOT prove fairness or arbitration correctness. Use when shaping stimulus timing, writing an arbiter/scheduler/picker test, or choosing a delay profile. |
READ FIRST: vault/handbook/INDEX.md (the handbook is the repo's memory; this skill is the signpost). Canonical: vault/handbook/dv/randomization.md.
ONE OF THREE ORTHOGONAL AXES (see rds-dv-axes): BFM = who drives (rds-dv-bfms); SEQUENCE = what traffic (rds-dv-axes); RANDOMIZATION = what timing. Authoritative docs: /docs/components/shared/components_shared_flex_config_gen.md and per-family components__randomization.md (axi4 has one).
Three layers, pick by what you configure: FlexConfigGen (named delay profiles - start here), FlexRandomizer (the engine, for constraint shapes no profile expresses), RandomizationConfig (per-field packet modes, not delays).
List profiles instead of guessing:
from CocoTBFramework.components.shared.flex_config_gen import DEFAULT_PROFILES
19 exist. backtoback = zero delay = full saturation. Others worth knowing:
fast, constrained (general default), bursty, stress, slow,
heavy_pause, chaotic.
RANDOM TRAFFIC DOES NOT PROVE FAIRNESS. Random profiles leave gaps, so a picker is never cornered and the request pattern decides who is served. A real round-robin arbiter that starved 2 of 4 clients passed its randomized fairness phase. For any arbiter/scheduler/picker: saturate deliberately, assert on PER-CLIENT outcomes (a Jain index > 0.3 on 4 clients passes with two starved), and mutation-check the assertion.
Two framework gaps recorded in the note: ArbiterMaster has its own private
profiles with no saturating option (use force_client_request), and
ArbiterCompliance.analyze_round_robin_compliance() is a stub returning
rr_efficiency: 1.0 unconditionally.
The handbook root is vault/handbook/INDEX.md - design/, dv/, fpga/, authoring/ areas, atomic notes, wikilinked. When you learn a durable lesson in this domain, ADD IT TO THE HANDBOOK NOTE, not to this skill.
Authoring a per-module reference page under docs/markdown (RTLCommon/RTLMath/RTLAmba) - the local .md style (header table, Overview, Architecture, Top-level Interface, Data model, Timing, Related, Test) and the SV header block that mirrors it. Use whenever you add or change an RTL block and need its docs/markdown page, and keep the book index in sync.
What kind of documentation lives where in this repo - handbook (method) vs docs/markdown (reader-facing) vs vault/Tasks (work) vs beside-code (CLAUDE.md, PRD). The rule that a beside-code README is a link, never a standalone guide, and that style guides / how-tos never live in the RTL tree. Use before creating, moving, or "tidying" any .md file, and when reviewing an area's meta-docs.
Coverage methodology - Verilator line/toggle coverage per component, functional coverage expectations, and the monbus packet-type coverage matrix. Use when adding tests, closing coverage, or preparing a board-gate sign-off.
The Sherpa documentation pipeline - md_to_docx with --style, LoF/LoT/LoW caption encoding, book indexes, RTL PDF generation, HAS/MAS vs operator guides. Use before generating or restructuring any deliverable doc.
Filelist rules - EVERY module MUST have a .f and MUST be registered in bin/filelists.toml. Components own their compile closure, consumers -f include, never hand-list another area's sources. Use when adding ANY new RTL module, test, or .f file.
Formal verification flow - SymbiYosys via sv2v flatten, in-RTL ifdef FORMAL properties, mutation-checking every new assertion, harness vacuity traps. Use when writing properties, regenerating proofs, or after changing any module with a formal dir.
