Re: [Iverilog-devel] Dumping SV structs and viewing them with gktwave

[<by...@nc...>]

---- ive...@li... wrote: 

> These other file formats have the same issue. They do not show the
> hierarchy. I did notice this in the gtkwave ChangeLog:
> 
> 3.3.48? 04aug13 ...
> ? ? ? ? ? ? ? ?  Added support for SV structures, unions, classes,
> ? ? ? ? ? ? ? ?  packages, programs, and interfaces.
> ? ? ? ? ? ? ? ?  ...

Chris,

Your simulator needs to support dumping them.  For example, for my day job I use VCS and it writes those hierarchy types to an FSDB file.  If I convert it to FST using vcd2fst (with the FsdbReader libraries linked in), they're visible exactly the same as in the FSDB.  I used FSDB's support as a model for FST's.

Note that the VCD parsers in gtkwave do support additional (non-1364 architected) hierarchy types and they all have their own special icons in the SST:

case 'm':       ttype = TREE_VCD_ST_MODULE; break;
case 't':       ttype = TREE_VCD_ST_TASK; break;
case 'f':       ttype = (GLOBALS->yytext_vcd_recoder_c_3[1] == 'u') ? TREE_VCD_ST_FUNCTION : TREE_VCD_ST_FORK; break;
case 'b':       ttype = TREE_VCD_ST_BEGIN; break;
case 'g':       ttype = TREE_VCD_ST_GENERATE; break;
case 's':       ttype = TREE_VCD_ST_STRUCT; break;
case 'u':       ttype = TREE_VCD_ST_UNION; break;
case 'c':       ttype = TREE_VCD_ST_CLASS; break;
case 'i':       ttype = TREE_VCD_ST_INTERFACE; break;
case 'p':       ttype = (GLOBALS->yytext_vcd_recoder_c_3[1] == 'r') ? TREE_VCD_ST_PROGRAM : TREE_VCD_ST_PACKAGE; break;

...forget about support in LXT, LXT2, etc.  They're old formats well over 10 years old not really worth extending.  FST can store a lot more useful information.  Looking at fstapi.h shows what is possible.  It supports VHDL as well (e.g., for the nvc compiler) so it is more flexible than the other formats.

-Tony