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AR# 43309

13.2 PlanAhead - CRITICAL WARNING: [Constraints-5] Cannot loc terminal 'a' at site AE28, Unknown instance type 'PULLDOWN'

Description

PlanAhead shows the following critical warning messages when implementing my design:

CRITICAL WARNING: [Constraints-5] Cannot loc terminal 'a' at site AE28, Unknown instance type 'PULLDOWN' [C:\xxx\xxxx\top.ucf:1]

The Design has a number of pads (IBUF/OBUFT) that have PULLUP/PULLDOWN components instantiated on their wires.  

PlanAhead shows PULLUP/PULLDOWN components as unknown components. 

After implementation the LOC constraints are removed from the netlist file (in the PAR NCD file).

Solution

To work around this issue, remove the PULLUP/PULLDOWN instance in the HDL file and give the PULLUP/PULLDOWN constraint in the UCF on the particular net.

This issue has been fixed in PlanAhead 13.3.

AR# 43309
Date Created 07/26/2011
Last Updated 02/02/2015
Status Active
Type Known Issues
Devices
  • FPGA Device Families
Tools
  • PlanAhead - 13.2