Lattice Radiant: How do i constraint a path with false path at Pre-Synthesis?

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• Lattice Radiant: Why does the constraint coverage did not improve after using set_false_path constraint?

  By Default, set_false_paths does not improve constraint coverage, however For Radiant 2023.1 or later, the user can use the Timing Command Line Option "-false_covers" to add in the false paths to the timing coverage. This can be applied on the ...

• How can the user set a false path on my pre-synthesis constraint files (SDC/FDC) between the PLL clock outputs if these are generated in the post-synthesis stage?

  To set this as false_path in pre-synthesis, user need to define the create_generated_clock on the SDC/FDC file as well. Just make sure that the create_generated_clock constraint at the pre-synthesis stage captures all of the properties of the PLL ...

• All Nexus / Radiant: Why can't users see reset signals on the timing analysis reports even without setting the set_false_path constraints?

  Resets are not timed or cannot be checked on the timing analysis reports if they are using Global/Set Reset (GSR) component. GSR will be used if the following are set: 1. GSR is instantiated on the RTL and set to the reset signal. 2. GSR-related ...

• Lattice Radiant / PLL: What compilation process or stage does the software automatically define the create_generated_clock constraints of the PLL clock outputs? Can the user use the generated clocks on other constraints define in the pre-synthesis stage (e.g. set_clock_groups, etc.)?

  Any clock output of the PLL has an automatically create_generated_clock constraint defined in the post-synthesis stage. Thus, user can use the generated clocks on their constraints as long as they are using post-synthesis constraints. If the user ...

• All Devices: Why does 'set_multicycle_path -hold' constraint is not propagated to Synthesis using Synplify Pro FDC file?

  Description: The issue is present using Radiant 3.1.1 or below on any of the available FPGA devices on the tool. Solution: There is a work around using the Tcl console in the radiant GUI, or if you opt to use the tool from the command line it is even ...