NAME

       extcheck  -  check  hierarchical  ext(5)  files for global node connectivity and summarize
       number of fets, nodes, etc.

SYNOPSIS

       extcheck [ -c cthresh ] [ -p path ] [ -r rthresh ] [ -s sym=value ] [ -C ] [  -R  ]  [  -S
       symfile ] [ -T tech ] root

DESCRIPTION

       Extcheck will read an extracted circuit in the hierarchical ext(5) representation produced
       by Magic, check to ensure that all global nodes (those to  which  a  label  ending  in  an
       exclamantion  point is attached) are fully connected in the layout, and then print a count
       of the number of various  items  (nodes,  fets,  etc)  encountered  while  flattening  the
       circuit.   The root of the tree to be processed is the file root.ext; it and all the files
       it references are recursively flattened.

       The following options are recognized:

       -c cthresh
              Set the capacitance threshold to cthresh  femtofarads.   Extcheck  will  count  the
              number  of explicit internodal capacitors greater than cthresh, the number of nodes
              whose capacitance is greater than cthresh, as well as the total  number  of  nodes.
              (Other programs such as ext2sim(1) use this option as a threshold value below which
              a capacitor will not be output).  The default value for cthresh is 10 femtofarads.

       -p path
              Normally, the path to search for .ext files  is  determined  by  looking  for  path
              commands  in  first  ~cad/lib/magic/sys/.magic,  then  ~/.magic, then .magic in the
              current directory.  If -p is specified, the  colon-separated  list  of  directories
              specified  by  path is used instead.  Each of these directories is searched in turn
              for the .ext files in a design.

       -r rthresh
              Set the resistance threshold to rthresh ohms.  Similar in function to -c,  but  for
              resistances.  The default value for rthresh is 10 ohms.

       -s sym=value
              It's possible to use special attributes attached to transistor gates to control the
              length and width of  transistors  explicitly,  rather  than  allowing  them  to  be
              determined  by  the  extractor.   These  attributes are of the form ext:w=width^ or
              ext:l=length^, where width or length can  either  be  numeric,  or  textual.   (The
              trailing  ``^''  indicates that these are transistor gate attributes).  If textual,
              they are treated as symbols which can be assigned  a  numeric  value  at  the  time
              ext2sim  is  run.   The  -s flag is used to assign numeric values to symbols.  If a
              textual symbol appears in one of the above attributes, but isn't  given  a  numeric
              value  via -s (or -S below), then it is ignored; otherwise, the transistor's length
              or width is set to the numeric value defined for that symbol.  (This option is  not
              currently used by extcheck, but it is common to ext2sim(1) and other tools that are
              written using the extflat(3) library)

       -C     Set the capacitance threshold to infinity.   Because  this  avoids  any  internodal
              capacitance processing, all tools will run faster when this flag is given.

       -R     Set the resistance threshold to infinity.

       -S symfile
              Each  line  in the file symfile is of the form sym=value, just like the argument to
              the -s flag above; the lines are interpreted in the same fashion.  (This option  is
              not currently used by extcheck, but it is common to ext2sim et. al.)

       -T tech
              Set  the technology in the output .sim file to tech.  This overrides any technology
              specified in the root .ext file.

SEE ALSO

       ext2dlys(1), ext2sim(1), ext2spice(1), magic(1), rsim(1), sim2spice(1), ext(5), sim(5)

AUTHOR

       Walter Scott

BUGS

       The -s mechanism is incomplete; it should allow quantities other than  transistor  lengths
       and widths to be specified.

                                                                                      EXTCHECK(1)