CycloneIII and CycloneIV pin to pin compatible?

[Altera_Forum]

Hello everybody, 

 i have a simple question,  i want to use EP3C25 - 144 pin EQFP package in my project and there is also EP4C22 - 144 pin EQFP package fpga.  are these pin to pin compatible?  Thanks and Regards..

[Altera_Forum]

Simple answer: No.

[Altera_Forum]

Thanks very much!.

[Altera_Forum]

More complex answer: Maybe 

 First of all, I don't think there is an EP4C22. Are you referring to the EP4CE22? I would assume you are as the EP4CGX22 is not available in the 144 pin EQFP package.  I haven't compared the specific parts in question, but in my limited experience I have found the Cyclone III and Cyclone IV E parts to be extremely similar. In the two cases where I compared, there was only a couple pins different between two similar parts from each family. If you avoid using these pins in your design it may be possible to make a board compatible with both.  Your best bet is to compare the pin outs yourself. If they are similar, try compiling your Quartus project for both parts to make sure there are no errors. Make sure you have a backup first. Answer "no" when you switch the device in Quartus and it asks you if you want to reset all I/O assignments. If you do get an error, you may be able to tweak your pinout to make it compatible with both parts.

[Altera_Forum]

I reviewed the pin C3 and C4 assignments for E144 package and must confess, that my first statement was too hasty. The two devices are actually almost compatible, JTAG, configuration pins and power supply seem to have mostly identical pin positions. Some pins are incompatible, buts thats basically the same with migration devices within a family. 

 But I have to compile an Excel table for an exact comparison.  P.S.: I found that only two pins (4 and 22) are showing differences. All other have identical assignments, also including optional functions. I however didn't check DQS group assignments.  I also checked compatibility of some F484 package devices. I found exact pin compatibility of EP3C16 with EP4CE15 and EP3C40 with EP4CE30 and EP4CE40. I have a design with EP3C16 and EPC40 migration compatibility, so the three EP4 devices can be used as a replacement. Thank you for raising the question and kevin for the correction.

[Altera_Forum]

first i thought this was a simple question for a pupil, but now i am glad that we have noticed that this was an important point which may help all altera users. 

 for both kevin and FvM, thanks for your help  Regards..

[Altera_Forum]

Hello everybody, 

 for a last check, i have made a pin to pin comparison according to the documents provided on altera website.   Document is attached.  for EP3C25 and EP4E22 EQFP package, result is;   there are 3 differences on pin numbers: 4-22-79   EPC3 EPC4  4- IO GND 22- CLK0 GND 79- IO GND  so, if we connect all of these three pins to GND, there will be no compatibility problems between these two fpga.  Regards..