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.