Signal <IOS0> is assigned but never used. This unconnected signal will be trimmed during the optimization process. Input <nBG_IOB> is never used. This port will be preserved and left unconnected if it belongs to a top-level block or it belongs to a sub-block and the hierarchy of this sub-block is preserved. Input <DBG> is never used. This port will be preserved and left unconnected if it belongs to a top-level block or it belongs to a sub-block and the hierarchy of this sub-block is preserved.