Net Connections in Area Visual Mode

The Net Connections by Area Visule Mode lets you visualize the nets enclosed in or crossing a specified rectangular area of the design and examine the properities of those nets.
To display net connections in an area, first select Net Connections in Area in the Visule Mode Panel.
Click Reload.  In the dialog box, you can enter the coordinates of two corners of the desired area, or you can drag a rectangle directly in the layout view.  You can also specify the types of nets to be displayed: signal and clock nets by default, and optionally power,  ground, tie-high, and tie-low nets.
Then click OK to update the display.

The local connections, shown in magenta, are completely enclosed by the rectangle. The global connections, shown in organge, are the nets that have one or more pins both inside and outside the rectangle. The pass-through connections, shown in red, have pins outside of the rectangle only; the nets are expected to pass through the rectangle without connecting to any pins inside the rectangle.

You can optionally turn off the display of flylines and show the connection pins instead by checking the "Show only pins" option in the Net Connections Area panel.
You can also separately enable or disable the display of local, global, or pass-through type pins or net connections by checking or unchecking the respective options in the Visual Mode panel.

The three types of net connections highlighted in the Net Connections in Area view traverse the designated rectangular area in different ways.
Connections are local if all the pins of the net are inside the designated area. Connections are global if one or more  pins of the net are both inside and outside the area. Connections are  pass-through if all the pins of the net are outside the area and the connections are expected to pass through the area.

In the net connections in area display, a bar graph shows the numbers of local, global, and pass-through nets. To get more infomation on those nets in a category, select the category in the bar graph and then click the List button.  This opens a table in a new dialog box. The table lists the local and hierachical net names, net types, number of pins, and other info. in the nets. From this table, you can change the types of net info. displayed, highlight specific nets in the layout, generate histograms of the net data, and export the data to a spreadsheet.

The net connection in area display capability lets you determine the net topology in a particular region and observe the properties of the nets in that area. This feature works with both routed and unrouted designs. You can analyze the nets that cross a specific area and use the info. to change the floorplan or add constraints such as blockages. For example, excessive local nets might imply that utilization changes are needed, or excessive global or pass-through nets might imply that floorplan or placement constraint changes are needed.