Hi!
I have been working on a design lately where I use a the Xilinx Spartan
3E starter kit board. I use a logic analyser to check the output on some signals which are assigned to the boards' J1, J2 and J4 connectors. Sometimes, I get some of the signals to not even be "connected" on the external pins. When this happens, I find that going in to the VHDL code and adding a few changes that are usually never related to the signals I want to observe in the first palce, fix things for me.Lately, I have tried verifying the FPGA after downloading a newly generated configuration to it. The verification came back with 3076 errors. When I look at the logic analyser trace, it seems to provide "most" of the signals except for one one that should be there but it is not.
Is there a way to obtain more info as to why thee would be so many errors during the programming of an FPGA? Are there some settings I may not be using correctly in the tool that causes the recompile to not be as clean as I think it should? Does the verification process pick up noise on te programming cable (I use the USB cable in this case)? Could the FPGA be damaged (static perhaps)?
I guess I am curious as to why this is happening. Most of the time things seem to work fine, but on the odd compile, something disapears.
Thanks for any help/hints.