Inter-region Bundles Dialog Box
Displays inter-region connection bundles, showing the relative connectivity between Logic Lock regions.
- Maximum source node-to-region fan-out— Specifies the maximum source node to region fan-out count to include in the bundle-creation algorithm. This allows you to filter the resulting bundle display, by excluding those regions having fan-out counts greater than the specified value.
- Minimum bundle width— Specifies the minimum bundle width to display. This feature allows you to filter the resulting bundle display, by excluding from the display those bundles with width less than the specified value.
- Show Bundles— Displays the inter-region bundles.
- Hide Bundles— Disables the display of inter-region bundles.
The Inter-region Bundles algorithm evaluates the fan-outs that exist between source nodes in any Logic Lock region and destinations in any other Logic Lock region.
In the above example, node A in Region_1 has one fan-out, to Region_2. Node B in Region_2 has four fan-outs— two to Region_1, one to Region_3, and one to a location outside any Logic Lock region.
Using this data, the algorithm determines inter-region fan-out numbers, based on the number of node-to-unique-region fan-outs between pairs of regions. In the case of regions 1 and 2, the inter-region fan-out number is two, because each region contains one node which fans out to the other region, making a total of two. In the case of regions 2 and 3, the inter-region fan-out number is one, because only one node fans out between the two regions.
The Maximum source node-to-region fan-out box allows you to specify an upper limit for the number of inter-region fan-outs to be considered by the algorithm.
For example, if you specify a Maximum source node-to-region fan-out value of 10, the algorithm calculates bundles only for those regions that share ten or fewer inter-region fan-outs. This method allows you to exclude more densely connected regions from the calculation.
The algorithm bundles the inter-region fan-outs into single lines that are drawn between regions in the Chip Planner. A number displayed next to the bundle signifies the bundle's width— the number of inter-region fan-outs represented by the bundle. The greater the bundle width, the greater the relative connectivity between regions.
The following example illustrates the inter-region bundles that would be drawn for the regions described above:
The Minimum bundle width box allows you to specify a lower limit for the bundle width to be displayed.
For example, if you specify a Minimum bundle width value of 5, the algorithm displays only those inter-region bundles with width equal to or greater than five. This method allows you to exclude more sparsely connected regions from the display.