Forum Discussion
Honored Contributorstratix ii survive at high temperature 150?
Our device needs to survive in very harsh environment, the temperature might be 150 degree. Now I'm going to use military device, which support -55 to +125 degree. I would like to do timing analysis for the design, but there are only two models (4_slow MIN_IND_fast, I do now not the temperature for each model, how can I know the parameter of each model?), I can not set any other operating condition. Is it possible to do timing analysis at 150 degree? I mean to create my own timing model and analyze?
11 Replies
Altera_ForumYou are right, it seems the only timing models available are -55°C and +125°C. You can't make you own timing model, you will probably have to constrain it at +125°C, add some extra margin in the fitter timing settings and run some tests yourself.
I doubt that Altera will guarantee anything at this temperature, but you can always try and contact your local FAE and see if they have any extra information or advice.- Altera_Forum
Hi Daixiwen,
Thanks very much for the reply. "you will probably have to constrain it at +125°C, add some extra margin in the fitter timing settings and run some tests yourself." Constrain it at +125°C, I guess you mean in setting, select operating temperature conditions at +125°C. I do not understand this "add some extra margin in the fitter timing settings", how to add extra margin in fitter timing settings? - Altera_Forum
Yes you are right, I meant specifying the temperature conditions.
For the extra margin, go to Assignments > Settings > Fitter Settings, and in the Fitter effort block, select "Auto Fit" and put the margin in "Desired worst case slack". I think you'll have to check yourself in the Timequest report that this margin was met on all clock domains. It is hard to give any specific margin value you should use, I don't know how slower the design can be when going from +125°C to +150°C. I recommend to have a look at the Timequest report, and specifically the "worst case timing paths" report, and try to design some tests you can run at +150°C that make extensive use of those paths. - Altera_Forum
Thanks a lot for your reply again!!!
With set fitter effort to standard fit, the worst setup slack is 151 ps, which is very tight. After set desired slack to 200 ps, I get setup violation (-247 ps), it goes worse. It seems this trick does not work for my design. Are there any other ways to improve margin? - Altera_Forum
You can use the timing advisor (Tools menu > Advisors > Timing Optimization Advisor) to check your project settings for options to change to have a better timing.
But those options are usually limited. If you still have problems after that then you will probably have to look at the VHDL code and try to make it more speed friendly (by adding pipeline stages for example). Here again the "Worst-Case Timing Paths" part of the Timequest report will help you find what you need to optimize. - Altera_Forum
Yes, I re-generate the Sopc system at each compile.
And there is ID component included in SOPC. Thanks very much !!!! - Altera_Forum
Before you run timing simulations, I wonder if you should inquire if the Stratix is able to survive any reasonable amount of time at those temps with Altera. I mean you are exceeding the specified temp range by 25 degrees, I am not sure that the Stratix will even work at those temps anymore. +5C might be still be OK but +25C is exceedind the limit quite a lot.
- Altera_Forum
Most dies can survive 175°C with no problem, just with a worse timing. The main problem can be reliability. They will probably have a shorter life due to higher mechanical constraints on the package. But it's hard to give even an order of magnitude...
- Altera_Forum
I see, thanks again!
- Altera_Forum
I have a question about timing model here.
The device we are using is EP2S60F1020I4, which can support military temperature up to 125 centigrade. Now we set operation temperature to -40 to 125 centigrade, after full compilation, we can check timing with Timequest Analyzer, according to this device, there are only two models: 4_slow and MAX _IND_fast, I'm wondering what temperature for each model, are they -40 and 124 respectively? If I choose temperature -40 to 100 centigrade, the timing models are still 4_slow and MAX _IND_fast, what centigrades are they now? Does the temperature setting affect place and route? In addition, can I first compile and route, then set different temperature to check the slack difference due to different temperature?
