vcd2lxt - Converts VCD files to interlaced or linear LXT files

vcd2lxt [VCDFILE] [LXTFILE] [option]...

Converts VCD files to interlaced or linear LXT files. Noncompressed interlaced files will provide the fastest access, linear files will provide the slowest yet have the greatest compression ratios.

-stats

Prints out statistics on all nets in VCD file in addition to performing the conversion.

-clockpack

Apply two-way subtraction algorithm in order to identify nets whose value changes by a constant XOR or whose value increases/decreases by a constant amount per constant unit of time. This option can reduce dumpfile size dramatically as value changes can be represented by an equation rather than explicitly as a triple of time, net, and value.

-chgpack

Emit data to file after being filtered through zlib (gzip).

-linear

Write out LXT in "linear" format with no backpointers. These are re-generated during initialization in gtkwave. Additionally, use libbz2 (bzip2) as the compression filter.

-dictpack <size>

Store value changes greater than or equal to size bits as an index into a dictionary. Experimentation shows that a value of 18 is optimal for most cases.

Note that you should specify dumpfile.vcd directly or use "-" for stdin.

vcd2lxt dumpfile.vcd dumpfile.lxt -clockpack -chgpack -dictpack 18

This turns on clock packing, zlib compression, and enables the dictionary encoding. Note that using no options writes out a normal LXT file.

vcd2lxt dumpfile.vcd dumpfile.lxt -clockpack -linear -dictpack 18

Uses linear mode for even smaller files.

Anthony Bybell <bybell@nc.rr.com>

lxt2vcd(1) vcd2lxt2(1) gtkwave(1)