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Honored Contributor
Honored Contributorunwanted erase in UFM
hi everyone, I'm working on a custom board. There is a Max2 on it and I store the serial number of our device in the UFM. Once, one of our customer power down the device and power up again...
Altera_ForumHonored Contributor
Honored ContributorThe UFM in Max II have very less write cycles (less than 100 right out of my head) see datasheet.
we were realy unlucky with the UFM and accessing it via spi was very unreliable. no matter if spi clock was 4MHz nor a few kHz. the spi signals had no over or undershots so we used 1 UFM as a mirrow of the other UFM as a fall back memory. but it happend so often that after power up both UFM delivered garbage via spi or the whole memory content was corrupted. thats why we decided not to use this UFM memory anymore. Our EPM570F100I5N talks with a EP2C70 via SPI, the 3,3V power supply is impedance controlled and stable external reset works the hdl inside max ii works but ufm not always. Same situation no spi command sent to max ii, just a power up.
