Micron Active Serial Configuration Arria 10

In our design we use a NOR Flash memory from Micron (MT25QU01GBBB8E12-0SIT) as configuration device and the FPGA Arria 10 (10AX027E4F29E3SG). We write to the Flash via the FPGA using a .jic file.

The direct programming of the FPGA via .sof file as well as writing to the flash memory works fine. All signals look good on the oscilloscope. The powerup sequencing works fine. And the FPGA configures automatically after reboot.

From time to time you can observe the error that the FPGA does not load its configuration from the flash after disconnecting and reconnecting the power supply. And that also doesn't work anymore if you reboot the FPGA again.

If you re-program the flash everything works and the FPGA configures automatically after a restart.

I read the .jic file from the flash memory (Examine) of a board on which the FPGA did not configure itself. Compared to the original programming file, there are many errors in the data.

Unfortunately I do not know how to isolate the error. It feels like the flash is corrupt. But nothing writes to the flash and the power supply looks good.

Does anyone have any idea what this could be?

P.S.:

Some more infos:

MSEL[2...0] Pins: 011 AS (x1 and x4) Standard POR

nSTATUS Pin is toggling between high and low with a periode of 3 ms.

We use AS x4 with a slow 12.5 MHz Internal Oscillator as Active serial clock.

We use compressed bitstreams.

All unused Pins are reserved as output driving ground.