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AR# 30198

10.1 Partitions - How do I add PULLUP and PULLDOWN constraints to my lower-level partition?


When I use a PULLDOWN or PULLUP constraint on an I/O in my lower-level partition, the following error occurs in MAP:

"ERROR:Pack:1107 - Unable to combine the following symbols into a single IOB component:

BUF symbol "IBUF" (Output Signal = IBUF)

PAD symbol "PAD" (Pad Signal = PAD)

PULL symbol "PAD_PULLDOWN" (Output Signal = PAD)

Symbol IBUF is not in the same Partition as symbol PAD_PULLDOWN. Symbol IBUF belongs to Partition /inst and symbol PAD_PULLDOWN belongs to Partition /top."

Why does this error occur and how do I resolve it?


This issue is fixed in the 11.1 IDS release.

To avoid this issue in previous tools, instantiate the PULLDOWN/PULLUP primitives in the same level of hierarchy as the buffer.

For information on how to instantiate the Verilog and VHDL primitives, please refer to the Libraries Guide.


AR# 30198
Date Created 06/11/2008
Last Updated 12/15/2012
Status Active
Type General Article