.TH EXT2DLYS 1 
.SH NAME
ext2dlys \- create a SCALD wire-delays file from a tree of .ext files
.SH SYNOPSIS
.B ext2dlys
[
.B \-d\ 
\fIpsPerPf\fR
] [
.B \-l\ 
\fIpsPerCentimicron\fR
] [
.B \-m\ 
\fIminmult\fR
\fImaxmult\fR
] [
.B \-o\ 
\fIoutfile\fR
] [
.B \-t\ 
\fIcapscale\fR
] [
.B \-D\ 
\fIdrivefile\fR
] [
.B \-I\ 
\fIiload\fR
] [
.B \-L\ 
\fInetfile\fR
] [
.B \-M\ 
\fIscaldmapfile\fR
] [
.B \-O\ 
\fIoload\fR
] [
.I "extcheck-options"
]
.I file
.SH DESCRIPTION
.I Ext2dlys
is used to produce a SCALD wire-delays file (in \fIdlys\fR\|(5) format)
on standard output, to be used in simulation and timing verification.
It computes the wire delay information from capacitance in the circuit
extracted from a layout by \fImagic\fR\|(1).
.PP
The filename \fIfile\fR given to \fIext2dlys\fR is the name of
the root \fB.ext\fR file of the extracted circuit,
and also of the \fB.net\fR file.
The \fB.ext\fR files, in \fIext\fR\|(5) format,
contain the capacitance to substrate for each
electrical node, specify the connectivity of the circuit, and also
give distance information.
The \fB.net\fR file, in \fInet\fR\|(5) format,
lists the nets and terminals in the circuit that will
be present in the \fB.dlys\fR file.
All terminals in the \fB.net\fR file are by default considered to be
inputs (receivers) unless explicitly identified as drivers in the
\fIdrivefile\fR given with the \fB\-D\fR option; see the description below.
In addition to identifying the terminals of interest, the \fB.net\fR file
gives the signal name associated with each
net as a comment line immediately prior to the list of terminals in the net.
.PP
The remaining arguments to \fIext2dlys\fR tell how this
capacitance and distance information is to be converted into delay, as
well as specifying the use of alternate files:
.TP
\fB\-d\fI\ psPerPf\fR
Used to turn capacitance into delay; one picofarad is equal to
\fIpsPerPf\fR picoseconds of delay.
The default value is \fB100.0\fR, or roughly what one would
expect if using 100 ohm drivers.
The value of \fIpsPerPf\fR is used only for drivers whose effective
on resistance hasn't been given explicitly in the \fIdrivefile\fR
specified with the \fB\-D\fR flag (see below).
.TP
\fB\-l\fI\ psPerCentimicron\fR
Used to turn distance into delay; one centimicron of distance
is equal to \fIpsPerCentimicron\fR picoseconds of delay.
.TP
\fB\-m\fI\ minmult\ maxmult\fR
Multipliers to convert estimated delays into best-case (\fIminmult\fR) and
worst-case (\fImaxmult\fR).
Both are \fB1.0\fR by default.
.TP
\fB\-o\fI\ outfile\fR
Write the output to \fIoutfile\fR (note that no suffix is implied)
instead of to the standard output.
.TP
\fB\-t\fI\ capscale\fR
Gives a scale factor by which units of capacitance in the \fB.sim\fR file
will be multiplied in order to give femtofarads.  \fICapscale\fR may be
a real number; its default value is \fB1.0\fR.
.TP
\fB\-D\fI\ drivefile\fR
Also used to turn capacitance into delay, but on a per-net basis.
Each line of the file \fIdrivefile\fR consists of a hierarchical
pin name (of an output driver) and its associated ``drive factor''
(equivalent to \fIdelay\fR in the \fB\-d\fR flag above),
namely the number of picoseconds per picofarad for the net
driven by that output pin.
Nets driven by a pin listed not in this file use the default
delay specified by \fB\-d\fR above.
If this file isn't given, we don't know for certain which pins
are the drivers in each net, so we arbitrarily pick one pin
per net and assume it is the driver.
.TP
\fB\-I\fI\ iload\fR
In addition to the capacitance reported in the \fB.sim\fR file for each
net, add an additional \fIiload\fR attofarads of capacitance for each
input on a given net to the total capacitance for that net.
(Inputs are counted only if they appear in the \fB.net\fR file.)
The default
value of \fIiload\fR is \fB0.0\fR, since it varies so much from one
technology to the next.
This option is provided to account
for extra transistor capacitance not computed by the extractor, such as
when the technology of the circuit being extracted is non-MOS (e.g, bipolar).
.TP
\fB\-L\fI\ netfile\fR
Instead of using \fIfile\fB.net\fR as the netlist file, use
\fInetfile\fB.net\fR instead.
.TP
\fB\-M\fI scaldmap\fR
If specified, then \fIscaldmap\fR is read (note no suffix implied)
to obtain a translation between
Magic terminal names and SCALD pin names.  
Each line in \fIscaldmap\fR contains a Magic name followed by a SCALD
name.  The Magic name is terminated by the first blank; the SCALD
name continues from the next non-blank character to the end of
the line, possibly including embedded blanks.
When writing the output file, the corresponding SCALD name is
used instead of the Magic name for each pin in a net.
See \fIdlys\fR\|(5)
for more details of the output file format.
.TP
\fB\-O\fI\ oload\fR
In addition to the capacitance reported in the \fB.sim\fR file for each
net, add an additional \fIoload\fR attofarads of capacitance for each
output on a given net to the total capacitance for that net.
The default
value of \fIoload\fR is \fB0.0\fR.  If only \fB\-I\fR and not \fB\-O\fR
is specified, \fIext2dlys\fR treats this as though both \fB\-I\fR and
\fB\-O\fR had been specified with the same values; inputs and outputs
are not distinguished.
.PP
In addition, all of the options of \fIextcheck\fR\|(1) are accepted.

.SH "SEE ALSO"
extcheck\|(1), ext2sim\|(1), ext2spice\|(1),
magic\|(1), dlys\|(5), ext\|(5)

.SH AUTHOR
Walter Scott