ESD test on cyclone 2

Hi.

We have board designed around Cyclone 2 in 240 pin package(QFP). On this board beside fpga is located memory(DDR RAM) and lvds converters.

In the order to done esd test I implemented simple test design which controll LEDs in VHDL and NIOS 2 processor. The processor uses internal memory na lvds links are not used.

So. I perform esd tests( 4KV - 10KV) on our board. It shows that our HDL design + soft processor (NIOS 2) are frequently reloaded duing esd test (also at 4KV). The most frequently reloading is performed when esd test is done around digital power supply (3.3V, 1,2V).

I suspect that motion is distributed trough power supply to FPGA, although I have implemented power supply according Altera recommendation.

I would like if anybody has experiences with esd test of cyclone 2 in this package?

Thank you in advance,

Amir Hasanovic