We have detected your current browser version is not the latest one. Xilinx.com uses the latest web technologies to bring you the best online experience possible. Please upgrade to a Xilinx.com supported browser:Chrome, Firefox, Internet Explorer 11, Safari. Thank you!

AR# 13171

7.0 SYNPLIFY - "WARNING:Ngdbuild:452- logical net 'net' has no driver." -- "WARNING:Ngdbuild:454- logical net 'net' has no load."


Keywords: Synplify, Synplicity, GND, VCC, NGD, NGDBuild

Urgency: Standard

General Description:
Synplify is leaving unnecessary nets unconnected after optimization, which results in numerous NGDBuild warning messages similar to the following:

WARNING:Ngdbuild:452- logical net "net" has no driver.
WARNING:Ngdbuild:454- logical net "net" has no load.


The only way to avoid these warnings messages is to turn off "preserve hierarchy" in Synplify as follows:


library synplify;
use synplify.attributes.all;
architecture top of top is
attribute syn_netlist_hierarchy of top : architecture is false;
-- Other coding


module top (clk, qout, a, b) /*synthesis syn_netlist_hierarchy=0 */;
/* Other coding */
AR# 13171
Date Created 11/13/2001
Last Updated 04/23/2007
Status Archive
Type General Article