vcd2lxt¶

NAME¶

vcd2lxt - Converts VCD files to interlaced or linear LXT files

SYNTAX¶

vcd2lxt [VCDFILE] [LXTFILE] [option]…

DESCRIPTION¶

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.

OPTIONS¶

-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.

EXAMPLES¶

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.

AUTHORS¶

Anthony Bybell <bybell@rocketmail.com>