Extraction

If no extraction directives are given, NETEX will create an output file that includes all of the nets that were built up by using connectivity or touching of conductors. However in many cases one will want to focus on a single net or a few critical nets. Not every field analysis program can handle the hundreds or thousands of nets that might be created from a complex package or board design.

The extraction directive allows one to specify a net or nets either by net name, node name or by coordinate. It also allows one to request either the proximity metal or to obtain a list of "nearby" nets.

This extraction section is optional and there can be multiple extraction directives in a single NJB file.

In the NJB file the extraction section looks as follows:

Extraction by Net Name

B_EXTRACT BYNAME clk5.txt PROXIMITY
CLOCK5
E_EXTRACT

Line 1 - must begin with B_EXTRACT. Then it is followed by BYNAME which indicates that NETEX should use the net name to extract net. This is followed by a file name. The results of this extraction directive are written to the specified file name. This may be followed by either PROXIMITY | NEIGHBOR. If Proximity then NETEX will add the proximity net to the output. If NEIGHBOR, NETEX will output all nets that cross the boundary defined by the expansion distance.

Line 2 - the net name. This must match a net name that is either specified in the NETS section or an automatically created net name. (though it is not clear how one would be able to know which automatically created name is of interest.) You can list as many net names here as you want or you can use a wild card expression to collect multiple nets.

Line 3 - E_EXTRACT. This closes the extraction directive.

Extraction by Coordinate

B_EXTRACT BYCOORD   clk5.txt NEIGHBOR
45.870 23.98  1
E_EXTRACT

Line 1 - must begin with B_EXTRACT. Then it is followed by BYCOORD which indicates that NETEX should use the coordinate to extract the net. This is followed by a file name. The results of this extraction directive are written to the specified file name. This may be followed by either PROXIMITY | NEIGHBOR. If Proximity then NETEX will add the proximity net to the output. If NEIGHBOR, NETEX will output all nets that cross the boundary defined by the expansion distance.

Line 2 - the coordinate and stackup position. This should be a coordinate on one of the conductor layers and the point must fall on a conductor. The stackup position is listed after the coordinate. If you wish to extract several nets then use additional lines for each coordinate/layer combination.

Line 3 - E_EXTRACT. This closes the extraction directive.

Extraction by Node Name

B_EXTRACT BYNODE diffpair.txt PROXIMITY
BF2
BF3
E_EXTRACT

Line 1 - must begin with B_EXTRACT. Then it is followed by BYNODE which indicates that NETEX should use the node name to extract net. This is followed by a file name. The results of this extraction directive are written to the specified file name. This may be followed by either PROXIMITY | NEIGHBOR. If Proximity then NETEX will add the proximity net to the output. If NEIGHBOR, NETEX will output all nets that cross the boundary defined by the expansion distance.

Line 2 - the node name. This must match a node name that is specified in the NODES section. Further, the node must have fallen on a valid physical net. You can list multiple node names or use a wildcard expression.

Line 3 - E_EXTRACT. This closes the extraction directive.