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.XX
astg_slow [-v debug_level] [-t tolerance] [-s] [-u]
[[-f|-F] external_delay_file] [-d default_external_delay] [-m min_delay_factor]
.PP
Remove hazards from the ASTG implementation, inserting delay buffers after some
ASTG signals. Delays are inserted so that no gate within the circuit
implementation can react as though the ASTG specified ordering of signals is
reversed in time.
.PP
It must be invoked after technology mapping (see \fBastg_to_f\fR for a
recommended script file).
.PP
The \fB-m\fR option specifies the amount by which all MINIMUM delays are
MULTIPLIED (this until the delay computation will understand min/max delays).
Of course 0.0 < min_delay_factor <= 1.0.  Default value: 1.0.
.PP
The \fB-t\fR option specifies the tolerance to be used during the hazard check
procedure (the larger the specified value, the more conservative is the
algorithm). Default value: 0.0.
.PP
The \fB-s\fR option specifies not to use the shortest-path algorithm when
computing the delays in the network. This might result in being overly
pessimistic (this option is only experimental).
.PP
The \fB-f\fR option specifies a file name to search for the minimum
delays between output signals and input signals of the ASTG (i.e. for those
signals that are not being synthesized). This can be useful if some information
about these signals is known either from the specification or from the
synthesis of another sub-component of the total asynchronous system. 
.PP
The file can also be
updated with the minimum delays between each input signal and each output
signal if the \fB-F\fR option is used in place of \fB-f\fR.
This allows for separate synthesis of various sub-components of an
asynchronous system. In this case iteration might be necessary to obtain
optimal results, and a warning message is issued when the stored information
is changed, and  a new iteration is required.
.PP
The \fB-u\fR option specifies not to remove hazards, but only to update the
external elay file (if appropriate). This can be used to remove hazards from a
set of Signal Transition Graphs that are synthesized separately (e.g. by
contraction). In this case, a first round of synthesis can be performed
on each Signal Transition Graph, followed by \fBastg_slow\fR 
with the \fB-F\fR and the \fB-u\fR options, to store the information on the
delay of the function implementing each signal. Then \fBastg_slow\fR can be
iterated among the Signal Transition Graphs with the \fB-F\fR option only until
convergence is obtained. The results should be comparable with synthesis and
hazard removal from a single Signal Transition Graph, but can be considerably
faster for large specifications.
.PP
The \fB-d\fR option specifies the default minimum delay between output signals
and input signals of the ASTG (if no information can be obtained from the above
described file). The default value is 0.0 (i.e. the environment responds
instantaneously), but this can be overly pessimistic, and result in an
unnecessary slow and large implementation.
