Quartus pin assignment of signals like HPS_DDR3_DQ

Hi folks,

I am following one of the manuals/tutorials at RocketBoard and I really like it. However I had a question which I couldn’t find an answer to. It has to do with the following.

For using the QSys system in the tutorial all kind signals should be assigned to pins. Also the externally exported signals of the custom IP should also be assigned to pins. However the manual does not say anything about this but it magically still works. Quartus does assign all kind of pins to signals/Node names but I have no clue on base of what Quartus makes those decisions. I have been searching the whole working directory folder tree but I cannot find any file which defines these pin assignments (except for the one I changed by hand). I think that those signal labels, like HPS_DDR3_DQ[x] are standard labels which are automatically assigned to the corresponding PIN on the current FPGA, but I haven’t manage to find any information about this. Is this assumption right?

In case it is, does this also main that migrating to another FPGA should not result in any problems if they both support the same functions/hardware? (I own a CycloneV SoCKit instead of DE10 which has, for example, the LEDs connected to other pins of the FPGA than the DE10).

Thanks in advance!


Hello wobbert,
You are particullary right. You need not assign pins like those for DDR3 memory because each model of FPGA has dedicated pins for this interface. Quartus knows, where these dedicated pins are situated. You can also find their possitions in manuals (in manual for Yours kit as well as in manual for the model of FPGA of Yours kit). More over, these pins are so well protected that You cannot assign they manually in PIN Planner (and I think nor in the Assignment Editor). It is probably right if You are not fable to find the possitions of pins for DDR3 in any file in the directory od Quartus project, I think that they are hidden somewhere in the database folder.
So do not think about it too much, it is done by Intel (Altera) for us.
I hope that this answer will help You a bit.

1 Like

Seems like the answer I was looking for. Thanks for the info :slight_smile: