Value change dump (VCD) (also known less commonly as "variable change dump") is an ASCII-based format for dumpfiles generated by EDA logic simulation tools. The standard, four-value VCD format was defined along with the Verilog hardware description language by the IEEE Standard 1364-1995 in 1996.
Value change dump (VCD), also referred to as variable change dump, is a text-based file format for capturing simulation data from EDA logic tools. The widely accepted four-value VCD format was formalized in conjunction with the Verilog language by the IEEE Standard 1364-1995 in 1996.