Knowledge Base Article
Why am I still getting a Critical Warning about Simultaneous Switching Noise (SSN) and crosstalk even though I am following the SSN and crosstalk reduction guidelines?
Description
Due to a problem in the Quartus® II software version 13.1 you may see the critical warning shown below, even though you have followed the Knowledge Base solution ID: rd10102013_979
Critical Warning (12888): Cross talk of LVDS Pin <design_pin_name> from SE I/O is too high. Reassign or move one or more of the following SE I/Os pins location and re-run the analysis again. Please refer to the guideline from the Knowledge Base solution ID: rd10102013_979 and ensure the total % of crosstalk for the following SE I/O pins does not exceed 100%.
This error may incorrectly appear under these conditions:
- When using a single ended IO standard other than 2.5V within the same or across different I/O banks with LVDS pins.
- When using 2.5V single ended IO across different I/O bank with LVDS pins.
Resolution
If you have identified that a warning is invalid, you can temporarily disable the critical warning by adding the following line in your .qsf file.
set_instance_assignment -name IO_MAXIMUM_TOGGLE_RATE "0 MHz" -to <design_pin_name>
This problem will be fixed in future release of the Quartus II software.