Tech Tip: Managing Specman esv File Size

When compiling e files on top of Specman, or when using the save command, Specman stores its state in an .esv file.  However, there are times when the .esv file can become quite large -- sometimes on the order of 100s of MB.

The good news is that Specman allows you to control the compression level of its .esv file and save valuable disk space by setting the config flag "esv_compression_level".  Values for compression level can range from 0 to 9.  A higher value means more compression, resulting in a smaller .esv file.  The default is 0, that is, no compression.  Here are two simple ways to set the desired compression level:

Method A
setenv SPECMAN_PRE_COMMANDS "set_config( misc, esv_compression_level,5)"

Method B

<'
extend sys {
  setup() is also
     set_config(misc,esv_compression_level,9);
  };
};
'>

Note that (A) will work for both the 'save' command and compiling the e environment, while (B) will work only for the 'save' command after setup() was called.

Finally, Specman will read compressed .esv files of any compression level regardless of whether a file's compression level is different from the current Specman compression level.

Ariel

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Ariel Melchior
Senior Engineering Manager
Cadence Israel