12-18-2019 02:56 PM
Due to an oversight, we designed a board with a driver that creates an oveshoot into one of the Spartan 6 I/O pins; typical overshoot is 4.6V with a duration of 4%. The questions are multiple as we have observed no degradation in the performance of the FPGA over months and an unlimited number of cycles (greater than 10MHz rate) - is there a reliability report that details what damage may occur to the pin (only a single I/O in a somewhat limited I/O application).
12-18-2019 03:27 PM
I'm sure that it's an absolute maximum rating issue.
You must stick to the rules under proper condition.
Refer page 2 of the following URL.
12-19-2019 03:37 AM
However, that does not answer the questions about what damage occurs and how much exposure to an overshoot to initiate the damage (and essentially, how where these limits determined).