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Honored Contributor
Honored ContributorFPGA instability after reset
Hi all, I am working with a custom Cyclone IV E based HW that is suffering from strange startup instability. The HW runs fine under various stress tests and temperature ranges when programmed...
Altera_ForumHonored Contributor
Honored Contributor --- Quote Start --- Just sometimes it happens that shortly after reset (toggling nCONFIG with a switch in my case) the system freezes. --- Quote End --- 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
