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Xilinx Constraints Guide

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STEPPING (Stepping)<br />

Architecture Support<br />

Chapter 4: <strong>Xilinx</strong> <strong>Constraints</strong><br />

The STEPPING (Stepping) constraint is assigned a value that matches the step level<br />

marking on the silicon. The step level identifies specific device capabilities. <strong>Xilinx</strong>®<br />

recommends that the step level be set for the design using STEPPING. Otherwise, the<br />

software uses a default target device.<br />

For more information on STEPPING, see <strong>Xilinx</strong> Answer Record 20947, Stepping FAQs.<br />

• CoolRunner-II<br />

Applicable Elements<br />

Propagation Rules<br />

• Spartan®-3A, Spartan-3E, Virtex®-4, Virtex-5<br />

The STEPPING attribute is a global CONFIG constraint and is not attached to any<br />

instance or signal name.<br />

Applies to the entire design.<br />

Syntax Examples<br />

The following examples show how to use this constraint with particular tools or<br />

methods. If a tool or method is not listed, you cannot use this constraint with it.<br />

UCF Syntax<br />

CONFIG STEPPING=”n”;<br />

where<br />

n is the target stepping level (ES, SCD1, 1, 2, 3, ...)<br />

UCF Syntax Example<br />

CONFIG STEPPING="1";<br />

<strong>Constraints</strong> <strong>Guide</strong><br />

UG625 (v. 13.2) July 6, 2011 www.xilinx.com 269

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