Stratix 10 settings -- what options are reversible?

[LowLevelGuy]

When using the Quartus GUI to specify device settings, there are various options such as "HPS debug without certificate",   "Disable JTAG",  "Disable HPS debug",  "Lock security fuses", etc... 

Does enabling these make it possible to go back?   For example, on the evaluation board, would it still be possible to alter the dip switches and program a different design than did not activate these security options, even if it meant programming the QSPI flash externally?

I'm basically having a bit of difficulty distinguishing runtime settings that are part of the bitstream and one-time physical efuse programming.  

Due to the very high cost of the Stratix 10 evaluation board,  I'm very much afraid of making a mistake that will be regretted -- I only have one board.

[Farabi]

Hello,

I am sorry for late reply.

As long as you dont enable the security feature, all bitstream you programmed into Stratix 10 can be safely overwritten.

regards,

Farabi

[LowLevelGuy]

But, that's what I'm trying to better understand...  

Does enabling "Disable JTAG" or "Lock security fuses" result in a permanent change?   Or is this just a runtime behavior that only remains in effect while the FPGA is configured?

Would it still be possible to alter the boot mode (such as using the DIP switches on the development board) to use JTAG instead of QSPI, power cycle the board,  and reprogram the QSPI flash using an ordinary factory image?

I realize quartus_pgm can be used to program fuses,  but it isn't clear to me if any of the project settings such as these could result in fuses being altered by simply loading the bitstream.

[Farabi · Accepted solution]

Hello,

Only if you used OTP(One Time Programmable) security feature, the burnt fuse is not reversible. The others security features will be able to overwrite as long as you followed the procedure correctly.

regards,

Farabi