EXTCHECK(1)						      General Commands Manual						       EXTCHECK(1)

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  num-
       ber  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 sym-
	      bol.  (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)