User Guide

Feelfreetoexperimentwiththeparametersettingsforyourlayout.
SMDBoardsWithSupplyLayers
Thefollowingprocedurehasbeenfoundeffective:
The supply signals are routed first. In general, a short track is wanted
fromaSMDcomponenttoaviathatconnectstotheinnerlayer.
Before altering the parameters, save the current (default) values in an
Autorouter control file (CTL file). Click on the button Save as.. in the
General tab of the Autorouter setup window and input any name, for
example, standard.ctl.
Now switch off the bus router and all the optimization passes in the Au
-
torouter setup. Only the routing remains active. Alter the following
costfactors:
cfVia=0Viasarewanted
mnVia=1Max.1viaperconnection
cfBase.1/16=30..99Shorttracks
inTop/Bottom
mnSegments=2..8shorttracks
Start the Autorouter, using the Select button, and choose the signals to
be routed. After the routing pass it is possible, if appropriate, to opti
-
mizetheresultmanually.
The rest of the connections are routed after this. Use AUTO to open
the Autorouter setup menu, and load the previous stored control pa
-
rameters with the Load.. button (standard.ctl). Adjust the values to any
specialwishesyoumayhave,andstarttheAutorouter.
This procedure is identical for both types of supply layer (automatically
generatedsupplylayer,orasupplylayergeneratedwithpolygons).
Whatcanbedoneifnotallsignalsarerouted?
Ifthishappens,checkyoursettings.
•
Hasasufficientlyfineroutinggridbeenselected?
•
Havethetrackwidthsgotappropriatedimensions?
•
Cantheviashavesmallerdiameters?
•
Havetheminimumclearancesbeenoptimallychosen?
If it is either impossible or unreasonable to optimize these values any
further, an attempt to achieve a higher level of routing may be made by
increasing the ripup level. Observe the notes in the section on the Num
-
berofRipup/RetryAttempts onpage 145.
153
TheAutorouter