iPA/iIR · Power & IR-drop analysis

# Core capabilities

# Activity-provenance power breakdown

iPA supports static (no activity file) and dynamic (VCD/SAIF) power calculation. In dynamic mode, iPA computes per-cell switching activity in each time window from the activity file and aggregates by module hierarchy. Via iPA.analyze, Agents get total_power, dynamic/leakage components, and per-module power breakdown—tracing exactly which functional scenario and submodule contribute most power.

# Power-to-IR-drop causal tracing

iIR builds on iPA power results to analyze IR-drop across the power grid, mapping high-power modules to grid nodes and IR-drop values. Agents can query the root-cause module for each IR-drop hotspot instead of receiving context-free voltage-drop numbers. That enables targeted local P/G reinforcement rather than blindly adding stripes globally.

# Automatic hotspot detection

iPA/iIR synthesize power density and IR-drop severity into a hotspot list. Each entry includes module name, coordinate bounds, power density, peak IR-drop, and severity (critical/warning/info). Agents can pass hotspot lists directly to iPDN as target regions for local P/G reinforcement, closing the power-integrity optimization loop.

# Agent calling patterns

iPA/iIR expose three equivalent calling protocols.

from ieda import Client

client = Client("http://localhost:9099")

# Dynamic power analysis with activity file
result = client.call(
    "iPA.analyze",
    design_ref="snap_7f3a",
    scenario="func_typical",
    mode="dynamic",
    activity_file=vcd_ref,
    intent_ref="power_profile_v1",
)

print(result.total_power)        # 128.5 (mW)
print(result.power_breakdown)    # {"dynamic": 94.2, "leakage": 34.3}
print(result.ir_drop_map)        # <binary grid>
print(result.hot_spots)          # ["core/alu", "core/l2_cache"]

# Static IR-drop check only
ir = client.call(
    "iIR.analyze",
    design_ref="snap_7f3a",
    pdn_ref="pdn_v3",
)
print(ir.worst_drop)           # 42 (mV)

// JSON-RPC over MCP
{
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "name": "iPA.analyze",
    "arguments": {
      "design_ref": "snap_7f3a",
      "scenario": "func_typical",
      "mode": "dynamic",
      "activity_file": "/data/vcd/func_typical.vcd"
    }
  }
}

// Response
{
  "total_power": 128.5,
  "power_breakdown": {"dynamic": 94.2, "leakage": 34.3},
  "ir_drop_map": "base64://...",
  "hot_spots": [
    {"module": "core/alu", "ir_drop": 42.0, "severity": "critical"},
    {"module": "core/l2_cache", "ir_drop": 28.3, "severity": "warning"}
  ]
}

# Dynamic power analysis
iPA::analyze_power -design snap_7f3a -scenario func_typical -mode dynamic -vcd /data/vcd/func_typical.vcd

# Static IR-drop analysis
iIR::analyze_ir -design snap_7f3a -pdn pdn_v3

# Query results
iPA::report_power_breakdown
iIR::report_ir_drop -worst 10
iPA::report_hotspots

# Input / output contract

Request Schema — iPA.analyze

Result Schema

# Role in the flow

                 ┌──────────┐
                 │   iPL    │  placement complete
                 └────┬─────┘
                      │
                      ▼
                 ┌──────────┐
                 │  iPDN    │  power grid
                 └────┬─────┘
                      │
                      ▼
                 ┌──────────┐
                 │  iCTS    │  Clock tree synthesis
                 └────┬─────┘
                      │
                      ▼
                 ┌──────────┐
                 │   iRT    │  routing complete
                 └────┬─────┘
                      │
                      ▼
┌──────────────────────────────────────────┐
│            iPA / iIR  ◆                 │
│  power calculation (static/dynamic)                │
│  IR-drop analysis → hotspot output            │
│  ↑ Input: placement + routing + RC parasitics + activity files │
│  ↓ Output: power breakdown + IR map      │
└──────────────────┬───────────────────────┘
                   │
                   ▼
          ┌──────────────┐
          │    iPNP      │  local P/G reinforcement
          └──────────────┘

# Related resources