UG445 Datasheet, PDF (5/24 Pages) –

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Preface
About This Guide
The CPLD I/O User Guide describes the behavior of the I/Os under various operating
conditions. It describes how to use the different termination modes, how to understand
thresholds, and how loading affects the I/Os.
Guide Contents
This manual contains the following topics:
• “Terminations” provides a brief description of the different terminations available in
Xilinx CPLDs. It also contains details on how to use termination.
• “Thresholds” describes in detail the conditions that affect the threshold levels. It gives
examples on how to use the I/V curves to understand what thresholds are under
nominal operating conditions.
• “Power, Sequencing, and Slew Rates” describes effects of powering, sequencing, and
slew rates on I/Os. It includes details on how much voltage can be driven into a
Xilinx CPLD and the behavior of the I/Os in different operating conditions.
Additional Resources
To find additional documentation, see the Xilinx Web site at:
www.xilinx.com/support/documentation/index.htm.
To search the Answer Database of silicon, software, and IP questions and answers, or to
create a technical support WebCase, see the Xilinx Support Web site at:
www.xilinx.com/support.
Additional Documentation
Xilinx ISE Software Manuals are available for download at:
www.xilinx.com/support/software_manuals.htm.
The following documents are also available:
• DS012 CoolRunner™ XPLA3 CPLD Data Sheet
This data sheet contains the electrical and functional specifications of the CoolRunner
XPLA3 CPLD.
• DS090 CoolRunner-II CPLD Family Data Sheet
This data sheet contains the electrical and functional specifications of the
CoolRunner-II CPLD.
CPLD I/O User Guide
www.xilinx.com
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UG445 (v1.2) January 14, 2014