Yes, the contents of User Flash Memory (UFM) in Intel® MAX® 10 FPGAs can retained in certain use cases.
When you see the below message in the Intel® Quartus® Prime Standard software while programming an Intel MAX 10 FPGA, Quartus Programmer erases the CFM as well as UFM content.
Warning (16139): Perform full chip erase and program at device index 1
The Programmer issues a full chip erase if the ICB bits of the new pof file does not match with the ICB bits of the previously programmed pof file.
To avoid a full chip erase of the Intel MAX 10 flash memory and to retain the UFM content:
- Ensure a factory default image exists in CFM0.
- Program CFM1 with the application image.
- Use Dual Configuration IP or CONFIG_SEL pin to switch between images or boot from CFM0 and CFM1.
This requires the design to have
- Configuration mode selected as Dual Compressed Images
- Verify Protect feature must not be enabled when trying to retain the UFM contents while programming.