Setup Time Calculator
Clock Period (ns)
Data Path Delay (ns)
Setup Time (ns)
Clock Uncertainty (ns)
Clock Skew (ns)
What is Setup Slack?
Setup Slack is the difference between the required arrival time and the actual arrival time of data at a flip-flop. It indicates whether the setup timing requirement is met.
- Positive Slack (> 0): Timing Passed ✅
- Zero Slack (= 0): Timing Exactly Met
- Negative Slack (< 0): Timing Violated ❌
Setup Slack Formula
Setup Slack = Clock Period − Data Path Delay − Setup Time − Clock Uncertainty + Clock Skew
Where:
- Clock Period (Tclk): Time between two clock edges.
- Data Path Delay (D): Delay of the combinational logic path.
- Setup Time (Tsetup): Minimum time data must remain stable before the clock edge.
- Clock Uncertainty (Tunc): Margin accounting for clock jitter and variations.
- Clock Skew (Tskew): Difference in clock arrival times between launch and capture flip-flops.