.\" /*
.\"  * Revision Control Information
.\"  *
.\"  * $Source: /vol/opua/opua2/sis/sis-1.1/common/src/sis/sis_lib/help/RCS/buffer_opt.1,v $
.\"  * $Author: sis $
.\"  * $Revision: 1.2 $
.\"  * $Date: 1992/05/06 19:04:01 $
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.XX
buffer_opt [-l #] [-f #] [-c] [-d] [-T] [-L] [-v #] [-D] node-list
.PP
Builds fanout trees for the nodes in the \fBnode-list\fR.
If no nodes are specified selects the nodes to be buffered
in order to improve performance of the entire network. The
network is assumed to be mapped.
.PP
The \fB-l #\fR option specifies the number of fanouts which
a node can have so as to be eligible for buffering. The
default is 2, hence any multi-fanout node is a candidate for 
buffering.
.PP
The \fB-f #\fR option specifies the transformations to use. Set the
three least significant bits indicate the use (value == 1) of
the transformations. xx1 to use the \fIrepower\fR transformation,
x1x to use an \fIunbalanced\fR transformation and 1xx to use the
\fIbalanced\fR distribution of signals. More than one transformation
can be set active. Thus to allow the algorithm full flexibility use
the value = 7 (111 in binary notation) which is also the default.
.PP
The \fB-c\fR option specifies that one pass be carried out.
The default is to iterate till no improvement is achieved.
.PP
The \fB-d\fR option allows the complex gates to be decomposed
into smaller ones so as to increase drive capability. By default
the complex gates are retained.
.PP
The \fB-L\fR option traverses the network from outputs to
inputs ensuring that for every node, the gate that implements it
does not drive a load greater than the \fImax_load\fR limit
specified for that gate. \fBTHIS OPTION IS NOT YET IMPLEMENTED\fR.
.PP
The \fB-T\fR option displays the circuit performance as the 
iterations progress. If the required times at the outputs are
not specified the circuit delay is shown, else the minimum
slack value is displayed.
.PP
The \fB-v #,-D\fR option are for debugging. The \fB-v #\fR option
is the most verbose and the amount of verbosity can be increased
by letting the argument for \fB-v\fR range from 1 to 100.
