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How does limited time .SOF file work ?


I am new, and I created simple program that turns LED ON/OFF via one switch on board. This is done via NIOS II. I then created program in Eclipse to do that. I programmed it, and it all worked fine as expected.

Three days later, I am unable to even fails. I re-generated the HW in Platform designer, then recompiled in Quartus Prime. Still unable to program the board. I noticed when launching Programmer from Quartus Prime, there is no Message Window to show why it fails, but if I launch it from Eclipse, I do see it, and it does say that there is time limited IP used, so I guess it might have expired, and that is the reason.

The only real HW I used is NIOS II. Maybe that is the IP it was referring to.


I really thought after programming the device, it will work for one hour, or until it is untethered, but it seems it is behaving seems it is a one-time limited ! If this is the case, I would say it is so unnecessary restriction, and hinders initial learning.

Anyway, I am hoping to get some explanation...


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2 Replies

Never mind. The problem was not related to IP license which is good.


Hi Imad,


During Intel FPGA IP Evaluation Mode, the Compiler only generates a time-limited device programming file (<projectname>_time_limited.sof) that expires at the time limit. Yes unfortunately it is one-time limited only and if you want to use your code after the evaluation time has expired, you need to buy the IP core implemented in your programming - otherwise you won't be able to program your FPGA. You can refer to link below for details