Value Change Dump (VCD and Extended VCD) SupportCategory : Simulation/VerificationThe VCD (Value Change Dump) file format is specified in the IEEE Std. 1364-1995 standard. The VCD file is an ASCII file containing header information, variable definitions, and variable value changes. The VCD files store information about value changes during simulation for nets and registers. You can export waveforms containing VHDL signals to a VCD file. Aldec users who target their designs to Xilinx devices can export VCD waveforms compatible with Xilinx XPower (Verilog Value Change Dump - Xilinx XPower support).