Intel® Quartus® Prime Software
Intel® Quartus® Prime Design Software, Design Entry, Synthesis, Simulation, Verification, Timing Analysis, System Design (Platform Designer, formerly Qsys)
Announcements
Intel Support hours are Monday-Fridays, 8am-5pm PST, except Holidays. Thanks to our community members who provide support during our down time or before we get to your questions. We appreciate you!

Need Forum Guidance? Click here
Search our FPGA Knowledge Articles here.
15556 Discussions

Cross Talk of LVDS Pin from SE IO is too high

JCrai
Novice
1,131 Views

Hi,

 

I am creating a project for the Cyclone V A5 F23 device, I am using all true lvds receiver pins in bank 3B and 4A. I have added other control single ended IO to both bank 3B and 4A but am getting this warning:

 

Critical Warning (12888): Cross talk of LVDS Pin lvds_rxda[0] from SE IO 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%.

 

   Info (12899): SE I/O from the bank contributed to 45.64% of the margin due to SSN

   Info (12900): SE I/O spare_lvltl[0] contributed to 20.72% of margin due to crosstalk

   Info (12900): SE I/O tp_gen[3] contributed to 8.28% of margin due to crosstalk

   Info (12900): SE I/O tp_gen[2] contributed to 12.65% of margin due to crosstalk

   Info (12900): SE I/O tp_gen[1] contributed to 7.42% of margin due to crosstalk

   Info (12900): SE I/O tp_gen[0] contributed to 18.48% of margin due to crosstalk

 

Firstly the warning states to keep the total % crosstalk for SSN should be less than 100%, the warning says the SE IO in the bank contributed 45.64% which is less than 100?

 

I have followed the KDB article (the excel to show you which pins to keep out of is hopeless to use by the way!) and the SE IO pins I have placed are at least 1 pin away from all LVDS signals but I still get the warning.

 

How should I proceed? Do I have to use the set max toggle rate assignment? which seems like a bit of a hack.

 

I am running Quartus Prime V15.1.2 build 193 standard edition.

 

Thanks

James

0 Kudos
1 Reply
Rahul_S_Intel1
Employee
238 Views

Hi ,

Can you please try the auto placement option.

 

Regards,

Rs

Reply