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  3. AR# 10021: 14.x Constraints - How do I apply an OFFSET constraint with Grouped I/Os?

AR# 10021

14.x Constraints - How do I apply an OFFSET constraint with Grouped I/Os?

Description

How do I apply an OFFSET constraint with the I/Os grouped?

Solution

The OFFSET constraint is described in (Xilinx Answer 10020). The syntax is very similar to that in (Xilinx Answer 10020), except for differences in the beginning of the constraints. This style of OFFSET constraint is recommended over the individual NET offsets.

The following is an example of UCF specification:

Make the Time group:

NET "net_name1" TNM=IOGroup;
NET "net_name2" TNM=IOGroup;

Make the group OFFSET:

TIMEGRP IOGroup OFFSET=IN 12 BEFORE "clock_net";

For more details on timing constraints, please see the Timing Constraints User Guide http://www.xilinx.com/support/documentation/sw_manuals/xilinx12_1/ug612.pdf
AR# 10021
Date 12/15/2012
Status Active
Type General Article
Tools More Less