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I'm using a custom SW that runs on NIOS and downloads the .rbf file via generic UART. I'm using the USB-Blaster just to run the NIOS code.
This is all has been verified and works just fine.
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This response is not clear. I understand that you can verify the flash, i.e., read back what you wrote. However, you did not answer the question; "Are you bit-reversing the data bytes before you write them to SPI Flash?". If you are not, then AS configuration will fail, since the data is not in the correct format expected by the FPGA configuration controller.
Can you program the EPCS device in AS mode using your USB-Blaster, or do you have another board with an AS connection to the SPI flash via a USB-Blaster? If you do, you can download that using Quartus, and read the data back using your NIOS II code, and you will see that the bytes are written to the flash in bit-reversed format. (I have an old UP3 board that I have used to confirm this).
Cheers,
Dave
Honored Contributor
