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AR# 20377

6.3.2 NGDBuild - 'NgdBuild:466 - input pad net 'bHD_DAT' has illegal connection"

Description

Keywords: error, NGDBuild, ngdbuild, 466, illegal, connection

Urgency: Low

General Description :
When IFDDRR and FDCE are instaniated on the same net, NGDBuild fails with the following error.

"ERROR:NgdBuild:466 - input pad net 'XXX' has illegal connection. Possible
pins causing this are:pin D on block XXX with type FDCE"

Solution

The IFDDRR components consist of one input buffer and two identical flip-flops (FDCPE). When FD flip-flop is also instaniated, the handling of IBUF for this flip-flop causes the tools to error out. A change request is filed against this.

To work around this issue, you can use two FD components to create the DDR flip-flop.
AR# 20377
Date Created 11/15/2004
Last Updated 02/21/2007
Status Archive
Type General Article