Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. VZT which stands for Verilog/VHDL Zipped Trace is a dumpfile format designed for use with GTKWave. Its main features are a very high compression ratio and support for multiprocessor acceleration during reads. For user convenience, access to VZT files is provided through reader and writer API calls. The reader and writer API closely mimic that of LXT2.A dumpfile is an output file used to save detailed step-by-step results of a simulation run for analysis, re-simulation, or design verification.