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)