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User constraint file. UCF files are used to interact with Xilinx's implementation tools. UCF files are unique to Xilinx.

A format for feeding constraints and other controls into the Xilinx® ISE® tools.



One of the three types of constraint files in FPGA design, the user constraint file (.UCF). Full name: user constraint file. The remaining two are netlist constraint file (.NCF file) and physical constraint file (.PCF file). Used to complete timing constraints, pin constraints, and area constraints. The relationship of the three types of constraint files is: the user writes a UCF file during the design input phase, and then generates the NCF file after synthesizing the UCF file and the design, and finally generates the PCF file after being implemented. UCF files are ASCII code files that describe the constraints of logic design, and can be edited with a text editor and Xilinx constraint file editor.


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