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Just sometimes it happens that shortly after reset (toggling nCONFIG with a switch in my case) the system freezes.
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The switch connects directly to nCONFIG?? That is not a good design. The nCONFIG signal has a timing requirement that needs to be met, eg. see tCFG
http://www.ovro.caltech.edu/~dwh/carma_board/fpga_configuration.pdf How can you ensure tCFG is met with a bouncing switch signal? Unless you have switch debouncing logic, all-bets-are-off, since you are potentially violating the device power-on-reset requirements.
Cheers,
Dave
Honored Contributor
