Signoff
Signoff timing closes all active modes and corners on extracted parasitics with validated constraints.
Closure is achieved across the scenario matrix, not by fixing only the single worst path shown first.
Buffering a high-fanout net can improve transition and delay, but added cells and routes must be checked in every hold corner.
Static Timing Analysis flow
Follow each stage in sequence. Every stage produces information needed by the next.
Signoff—visualized
This technical view uses the actual structures and relationships associated with this stage, followed by its key terms.
Understand every concept
MMMC analysis
What it is: MMMC analysis is a core concept within Signoff. It describes the information, structure, or analysis engineers use at this stage of the Static Timing Analysis flow.
Why it matters: Understanding it helps you interpret the stage correctly, avoid incorrect assumptions, and connect the result to the next implementation or signoff step.
Where it fits: This topic belongs to module 4, Signoff, and its output supports the stages that follow.
Practical example: Engineer workflow: Run MMMC analysis and summarize failing path groups. Buffering a high-fanout net can improve transition and delay, but added cells and routes must be checked in every hold corner.
Path-based analysis
What it is: Path-based analysis is a core concept within Signoff. It describes the information, structure, or analysis engineers use at this stage of the Static Timing Analysis flow.
Why it matters: Understanding it helps you interpret the stage correctly, avoid incorrect assumptions, and connect the result to the next implementation or signoff step.
Where it fits: This topic belongs to module 4, Signoff, and its output supports the stages that follow.
Practical example: Engineer workflow: Classify constraint, clock, cell, net, crosstalk, or logic causes. Buffering a high-fanout net can improve transition and delay, but added cells and routes must be checked in every hold corner.
Timing ECO strategy
What it is: Timing ECO strategy is a core concept within Signoff. It describes the information, structure, or analysis engineers use at this stage of the Static Timing Analysis flow.
Why it matters: Understanding it helps you interpret the stage correctly, avoid incorrect assumptions, and connect the result to the next implementation or signoff step.
Where it fits: This topic belongs to module 4, Signoff, and its output supports the stages that follow.
Practical example: Engineer workflow: Choose an ECO that fixes root cause with minimal side effects. Buffering a high-fanout net can improve transition and delay, but added cells and routes must be checked in every hold corner.
Work through it step by step
- 1
MMMC analysis
Run MMMC analysis and summarize failing path groups.
- 2
Path-based analysis
Classify constraint, clock, cell, net, crosstalk, or logic causes.
- 3
Timing ECO strategy
Choose an ECO that fixes root cause with minimal side effects.
- 4
MMMC analysis
Re-extract, rerun all scenarios, and verify no regressions.
Explore each topic
01MMMC analysis
Understand the concept, connect it to the ASIC flow, study the report or behavior it produces, and apply it in a guided exercise. Check the result against the module goal before moving forward.
02Path-based analysis
Understand the concept, connect it to the ASIC flow, study the report or behavior it produces, and apply it in a guided exercise. Check the result against the module goal before moving forward.
03Timing ECO strategy
Understand the concept, connect it to the ASIC flow, study the report or behavior it produces, and apply it in a guided exercise. Check the result against the module goal before moving forward.
Completion checklist
- ✓ All required scenarios are active
- ✓ Noise and crosstalk settings are correct
- ✓ ECO netlist and layout match
- ✓ Final reports are reproducible
Practise with open-source tools
These are official third-party GitHub projects selected for this learning path.