User Guide

mnVia0..30
Controls the maximum number of vias that can be used in creating a
connectingtrack.
mnSegments0..9999
Determines the maximum number of wire pieces in one connecting
track.
mnExtdSteps0..9999
Specifies the number of steps that are allowed at 45 degrees to the pre
-
ferreddirectionwithoutincurringthevalueof cfExtdStep.
Seealso cfExtdStep.
7.6 NumberofRipup/RetryAttempts
Due to the structure of the Autorouter there are some parameters
which influence the ripup/retry mechanism. They are set in such a way
that they offer a good compromise between time demand and routing
result.Theusershouldthereforeonlycarefullychangethevaluesfor
mnRipupLevel, mnRipupSteps and mnRipupTotal whenneeded.
As a rule, high parameter values allow for many ripups but result in in
-
creasedcomputingtimes.
To understand the meaning of the parameters you need to know how
therouterworks.
To begin with the tracks are routed one after the other until no other
path can be found. As soon as this situation occurs, the router removes
up to the maximum number of already routed tracks (this number has
been defined with mnRipupLevel) to route the new track. If there are
eight tracks in the way, for example, it can only route the new track if
mnRipupLevel isatleasteight.
After routing the new track, the router tries to reroute all the tracks
which were removed. It may happen that a new ripup sequence must be
started to reroute one of these tracks. The router is then two ripup se
-
quences away from the position at which, because of a track which
could not be routed, it started the whole process. Each of the removed
tracks which cannot be rerouted starts a new ripup sequence. The maxi
-
mum number of such sequences is defined with the mnRipupSteps
parameter.
The parameter mnRipupTotal defines how many tracks can be removed
simultaneously.Thisvaluemaybeexceededincertaincases.
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TheAutorouter