We have detected your current browser version is not the latest one. Xilinx.com uses the latest web technologies to bring you the best online experience possible. Please upgrade to a Xilinx.com supported browser:Chrome, Firefox, Internet Explorer 11, Safari. Thank you!

AR# 5429

12.1 Constraints - Prohibiting multi-purpose configuration pins


To simplify my board design, I want to prohibit multi-purpose configuration pins.

What are these pins, and how are they prohibited?


Several special purpose pins are available for user I/O after configuration. The majority of these pins require a direct instantiation in order to be used (for example, TDO, MD1, etc.). Specific primitives must be assigned to utilize these pins, and they cannot be prohibited or pin-locked.

However, PAR uses a number of special purpose pins, and these pins can be prohibited by adding the following to the UCF:

Special purpose pins are dependent upon package, not family. You can find out more about special purpose pins for a specific device in the appropriate device data sheet.

AR# 5429
Date Created 08/21/2007
Last Updated 12/15/2012
Status Active
Type General Article