Cyclone IV shortcircuit in VCCint causes

[CG7]

Hi,

I've got a custom board with EP4CE6 on it, the board works but sometimes, it fails (defect seen on 6 boards).

The fail seems to happen at startup.

After inspection the power rail VCCint of the FPGA is in shortcircuit (less than 5 ohms).

I've checked the power supplies, there is no overshoot, the startup time is ensured and their rise is monotonous.

So my question is : what are can lead to this shortcut ?

- overvoltage ? if so what power rail can be involved ?

- cold sparing problem ?

- configuration problem ?

    => For me, there is a checksum in the bitstream preventing this to happen.

- can an overcurrent on an IO lead to VCCint shortcut ?

[CG7]

My design uses a high frequency clock.

In some buggy cases, I suspect that the frequency of this clock may be way too high (maybe reach 1GHz), in this case, would it be possible that the FPGA core goes into short circuit ?

The input is LVDS, is there a failure path between vccint and VCCA ?

[AqidAyman_Intel]

Hello,

May I know what is failing during the startup? Can you elaborate more on this?

If possible, you can also share if there is any snapshot on the relevant issue that might help.

Thank you.

[AqidAyman_Intel]

Hello,

Any update on the request I posted in the previous comment?

[AqidAyman_Intel]

As we do not receive any response from you on the previous question/reply/answer that we have provided, please login to ‘https://supporttickets.intel.com’, view details of the desire request, and post a feed/response within the next 15 days to allow me to continue to support you. After 15 days, this thread will be transitioned to community support. The community users will be able to help you on your follow-up questions.