Design Observer · 设计的可解释镜头

# 核心能力

# 1. Summarize

对任意 snapshot 生成结构化摘要。包括 cell/net 统计、关键路径延迟分布、拥塞热点坐标、功耗分布热区、时钟树深度与 skew。Agent 无需解析原始数据库即可快速获取设计的高层概览。摘要输出为结构化 JSON，可直接喂入 LLM context 或作为 Model Router 的输入特征。

# 2. Diff

比较两个 snapshot 的结构化差异。输出三类变化集：哪些 cells 变了（位置、尺寸、类型）、哪些 nets 重布了（拓扑变化、层变化）、timing 如何变化（关键路径的 slack delta、新增违例、消失违例）。Diff 结果可直接传给 Agent Planner 作为 "what changed" 信号。

# 3. Explain

解释某次变更的因果链。例如：为什么 resize 这个 cell 导致那条 path 变慢？Observer 追踪电容变化 → 驱动能力 → 过渡时间 → 单元延迟的因果链条，输出可读的因果步骤。每一步附带量化数据——不只是"变慢了"，而是"+42ps，因为 fanout cap 从 0.08pF 增到 0.15pF"。

# 4. Root Cause

从违例追溯到根因。输入一个 DRC violation 或 timing violation，Observer 回答三个问题：哪个改动引入的（改动追溯）、哪个 Agent proposal 导致的（决策追溯）、有哪些可能的修复路径（修复建议）。链路：violation → diff → change → candidate → agent intention。

# Agent 调用方式

Observer 提供四项原语的统一调用接口，Agent 通过一个 observe_type 参数切换不同的观察模式。

from ieda.observer import DesignObserver

obs = DesignObserver("http://localhost:9110")

# Summarize: get design overview
summary = obs.observe(
    design_ref="snap_b",
    observe_type="summarize",
)
print(summary.cell_count)     # 45231
print(summary.critical_paths) # [{"name":"clk_core","slack":-0.12},...]

# Diff: compare two snapshots
diff = obs.observe(
    design_ref="snap_b",
    observe_type="diff",
    reference_ref="snap_a",
)

# Root cause: trace violation to agent proposal
rc = obs.observe(
    design_ref="snap_b",
    observe_type="root_cause",
    violation_ref="DRC_M1_SPACING_x1245_y330",
)
print(rc.introducing_change)  # "cell_move_u_alu_0"
print(rc.agent_proposal)      # "candidate_c42_a"

// Summarize request
{
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "name": "observer.observe",
    "arguments": {
      "design_ref": "snap_b",
      "observe_type": "summarize"
    }
  }
}

// Diff request
{
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "name": "observer.observe",
    "arguments": {
      "design_ref": "snap_b",
      "observe_type": "diff",
      "reference_ref": "snap_a"
    }
  }
}

# Summarize design state
observer observe -design snap_b -type summarize

# Diff two snapshots
observer observe -design snap_b -type diff -reference snap_a

# Explain a change
observer observe -design snap_b -type explain \
  -change cell_resize_u7

# Root cause analysis
observer observe -design snap_b -type root_cause \
  -violation DRC_M1_SPACING_x1245_y330

# 输入/输出契约

ObserveRequest

ObserveResult

# 相关资源