General Description: My design contains multiple top-level sheets and signals that are connected from sheet-to-sheet. NGDBuild is reporting the following error:
"ERROR: basnu - logical net "net_name_int" has both active and tristate drivers."
(or "ERROR: basnu - logical net "net_name_int" has multiple drivers.")
This error occurs when the design uses I/O terminals for nets and/or I/O markers for busses to connect signals from one top-level sheet to another top-level sheet.
I/O terminals should ONLY be used to connect signals between levels of hierarchy (i.e., to connect a lower-level schematic to a macro symbol). To connect signals between schematic sheets on the same level, simply leave the net dangling, and be sure it has the same name on both sheets -- the name correspondence will ensure the logical connection.
For all signals that connect one top-level sheet to another:
a. You must redraw nets to use hanging wires: - Draw the net and right-click. - Go to the "Add net or bus name" icon in the left-hand toolbar.
b. Name the net.
a. Double-click on the desired bus. b. Select "NONE" for I/O marker.