How Does Inverse Temperature Dependence Affect Timing Sign-Off

摘要

In this work, we demonstrate that inverse temperature dependence is a complicated issue as it depends on many different factors such as manufacturing process, supply voltage, type of cells, etc. It makes ITD very difficult to be modeled in the tools. The relationship between temperature and path timing might be non-monotonic due to ITD, which threaten the effectiveness of the timing sign-off flow. Adding margin is not feasible as it makes design process more difficult. In order to detect the critical paths affected by ITD in pre-silicon stage, timing analysis at additional temperatures is required on selected paths. Once such affected paths are identified, swapping is applied on suspicious cells that are affected by ITD to low VTH devices.