Log-To-SPICE Conversion


        Harold Levy of Caltech modified the LOGNTK program to create a
  new program, LOGSPC, that creates SPICE decks instead of .ntk files.
  The tool is used identically to LOGNTK, so the manual section above
  describes LOGSPC also. The command to invoke the tool is :logspc, and
  configuration information is in the file lib/logspc.cnf. The FET7
  series works with LOGSPC, supported by the LAMBDA command. The FET
  models NSPC1 and PSPC1, contributed by Bhusan Gupta at Caltech, are
  perfect for use with LOGSPC.  These gates also simulate in analog;
  however, these models are considered "experimental" as opposed to
  "standard" models in analog, and are not supported by the chipmunk

        A few additional commands have been built into LOGSPC to better
  support SPICE capabilities.  Note that the SIZE and STRENGTH commands
  of LOGNTK are ignored in LOGSPC, and that the following commands are
  used instead:
          NBULK: signal-name
          PBULK: signal-name
                    These commands assign explicit names to the implicit
                    bulk terminals for 3-terminal FET (e.g. p/n-FETs 4 and 5)
                    and bipolar (e.g. NPN1, PNP1) models.  The signal-name
                    is output in capitals unless quoted.
          LAMBDA: number
                    This command assigns an explicit lambda value (in
                    microns) to the FET7 model series.
          CHLEN: number
                    This command assigns an explicit channel length (in
                    microns) to FET models using w/l ratios (e.g. p/n-FETs
                    4, 5, and 6).
          PRE: filename
          POST: filename

		    Specifies a file for inclusion into .spc files before
                    and after netlist.

  Also note that as of LOGSPC version 0.5b the ability to extract VDIFF
  gates is provided.  This feature may be shut off with the command

  Finally, the TRANS command has been extended, to supporting adding new
  gate types to logspc, as shown in the example below.


  Copy the files chipmunk/log/lib/{spctest.lgf,pre.spc,post.spc} to your
  directory, and examine and run logspc on spctest.lgf, to see the features
  described above in action.

	The supplementary toolkit includes companion programs to LOGSCP,
  that simplify using LOGSPC output with other tools. These tools are located
  in the spc-tools subdirectory of the toolkit. Three scripts are included:

         sf:  Flattens hierarchical LOGSPC (version 1.0) output.

         ss:  Converts output from "sf" into UCB SIM format for use with
              UW's "gemini" layout-versus-schematic (LVS) comparison program.

     ucbsim:  Appends "format: UCB" to the first line of SIM files generated
               by ext2sim.

john [dot] lazzaro [at] gmail [dot] com