Chapter 7
Autorouting and Autoplacement
7-2
ni.com
Note
This is only active when an unconnected pad corresponding to that net is selected.
Autoroute»Autoroute Selected Buses
Use to autoroute selected buses. Refer to the
section for
more information.
Autoroute»Start Optimization
Use to optimize the placement of traces. Refer to the
section
for more information.
Autoroute»Autoroute/place Options
Use to set up router and placer functions. Refer to the
sections for more
information.
Autoplacement of Parts
The following sections explain how to use the autoplacer to place parts.
Pre-Placing Parts
You may wish to pre-place certain parts (for example, holes) before
autoplacing other parts.
Complete the following steps to lock any pre-placed parts so they will not
be moved by the autoplacer:
1.
Select the pre-placed parts and choose
Edit»Lock
.
2.
You can also lock parts in place from the
Parts
tab of the
Spreadsheet
View
. Refer to the
, for more information.
Understanding How the Autoplacer Works
The autoplacer automatically places all unplaced parts onto your board
according to group settings you can specify. It uses a rip-up and retry
algorithm to find the best part positioning. As the autoplacer runs, the status
line at the bottom of the screen indicates how many autoplacement passes
have been completed. It also indicates how many parts have been placed
and how many pins have been swapped (when the autoplacer performs
pin/gate swaps). If the autoplacer cannot place all the parts, it returns a
message indicating how many parts are still unplaced in the
Results
tab of
the
Spreadsheet View
.
