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ID: 1587
实例类型: faq
分类: Implementation
相关: Timing Analysis
产品系列: All FPGA

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What are the different factors that affect device speed, temperature and voltage selection during software timing analysis?

Software uses different temperatures and voltages for timing analysis based on the following factors:



  1. Commercial vs. Industrial Part selection.:

    1. Commercial part selection enforces the following DEFAULT temperatures for Setup and Hold analysis (based on the operating conditions defined in the data sheet). For  Example, for an LatticeECP2/M Device, the following temperatures are used:  Setup: 85 C Hold: 0 C
    2. Industrial part selection enforces the following DEFAULT temperatures for Setup and Hold analysis (based on the operating conditions defined in the data sheet). For  Example, for an LatticeECP2/M Device, the following temperatures are used:: Setup: 100 C Hold: -40 C

  2.  You can override these default settings by applying temperature and voltage preferences in the LPF file. You can view the full list of LPF preferences, including temperature and voltage preferences, by performing the following steps, depending on the Lattice software tool you are using:


    • from the  Lattice Diamond software tool: select Help-> Lattice Diamond Help. In the new pop-up web browser, select Constaints Reference Guide -> Preferences
    • from the  Lattice ispLEVER software tool: select Help-> ispLEVER Help. In the new pop-up web browser, select Constaints Reference Guide -> Preferences

Speed Grade selection for timing analysis  on the other hand depends on the following factors:



  1. Place & Route Trace uses by default the user selected part speed grade for setup timing analysis and the -m speed grade for hold timing analysis.
  2. IO TIMING analysis by default sweeps through all  faster speed grade including the user selected  part speed grade