03-11-2019 08:15 PM
What can I do if I want to detect the highest frequency of the circuit running on the FPGA?
Hello, I am doing an experiment recently. I want to test the highest frequency of my circuit running on the FPGA board. What method can I adopt?
I have two zedboard and two ZC702 boards in my hand. Thank you for your reply!
03-14-2019 09:39 AM
You can always strat with the DC switching UG. it will tell you how fast any of the Buffers, or other primitives can run. That puts the ceiling on the max speed. But realistically it will be well below that.
If you want to know how fast a specific implementation run could go, look at the amount of positve slack in the worst reported path. (It will be the path it tells you in the report_timing_summary at the top)
You can increase the period of the driving clock by that much time, and then rerun the report_timing_summary(Do not reimplement) with the updated clock period, and see if it still passes. If it fails, you need to back off a little. Do that until the slack is something like 0.000 or 0.001
Thats about as fast as you can run your current implemented design. The tool checked that all the requirments where still met and you don't have any negative slack being driven by a clock at the specified speed.
But this only reflects for that one implementation. You can then rerun it with that faster speed. And it might give you more margin, and you can repeat, and keep turning on more effort to try and meet those higher requirments.
But this isn't a good way to go about things. You should start with a target on how fast you need to run to accompish what you want to do.
And tell the tool that's how fast it needs to be. And if it can't do it, look into where it is unable to meet the requirment and either redesign, ask it to put more effort, or determine if you can run at a slower rate.
If you are having issues meeting a specific requirment, you should post the details on what you are trying to do and the result you are getting.
Which more specific feed back can be provided.
03-14-2019 10:42 AM
basicaly try it.
The tools run till they have meet your timming constraints, no more.
so the maximum is not found till you push the tool.