07-10-2011 05:14 PM
Can anyone tell me where I could find the I/V Curves for the XC9500 family with VCCIO = 5V0. The XAPP150 commonly referred to seem to show the curves for VCCIO = 3V3.
Thank you !
07-10-2011 05:44 PM - edited 07-10-2011 05:51 PM
Here (in .ZIP archive) are the IBIS models for 9500.
The download page for this .ZIP archive is here.
In XAPP150, there is a link on the first page for Xilinx IBIS files. Clicking on the link brings you to a page with a 'files moved' warning, and a link to the new "Main File Archive page". From there you click on "All downloadable files" link for the file repository.
-- Bob Elkind
07-10-2011 08:31 PM
I'm a hobbyist with some experience but never actually paid attention to what IBIS models were. Thanks for having me work my way into that !
Now, I see that the ISE actually generates the IBIS model for my project. I can work my way down the file and find the info I'm looking for. But I'm just wondering now if the ISE can plot the diagram of the curves or if some readily available software can ?
Thanks again !
07-11-2011 02:49 PM
There's a free IBIS viewer here, and I originally downloaded the full suite with an eval license, but
it's not clear to me now whether that option is still available. There are others on the web...
07-11-2011 04:14 PM
After looking more at the IBIS model data (both in the file and using a tool I fond on the NET: Sintecs IBIS Development Studio), I'm still puzzled.
My goal is to find the VOL and VOH of a port if I sink or source 1mA in one case, 10mA in another, and 20mA in a third case.
So I looked at the IO_01 Model (Not Slow and VCCIO = 5V). The pulldown data should give me the VOL values I'm looking for right ? And the pullup data should give me the VOH values ?
So from the pulldown data, I managed to find what I was looking for :
1mA : VOL = close to 0.0V (typical)
10mA: VOL =around 0.1V (typical)
20mA: VOL =around 0.2V (typical)
But when looking at the pullup data, I got confused. At 1mA, I was expecting to find a value close to 5V, but the data says something between 1.3V and 1.4V.... I don't get it...
Any help with interpreting the data ?
07-12-2011 01:07 PM
Also note that for SINTEC the default plot of the pullup function is Vcc-relative. You can change the settings
to ground relative using Ctrl-Shft-G to see the curve referenced to ground. Also if you care about what
happens outside the normal voltage range you can have the plot combine the pullup and Vcc clamp