10CL006 vs EP4CE6 compatibility

[JStan7]

We made a design with 10CL006YU256I7G...  At the moment this FPGA is difficult to buy, because of ???. Therefore I checked the predecessor from Cyclone IV series. The EP4CE6U14I7N. It seems this part is 95% pin compatible and we can use the same PCB because the different pins are not used. Thats good

questions: 

1. Can I use for the EP4CE6 the same programming file (*.rbf) as for the 10CL006? It seems to work, but is this correct and allowed?
2. Is there a way to detect from inside the FPGA-firmware which FPGA is populated on the PCB e.g. by reading back an FPGA-ID-code by the running NIOS core. It seems the JTAG-ID is the same for both FPGA's

[YuanLi_S_Intel · Accepted solution]

It is not recommended but it works sometimes. The reason is RBF is a raw binary data, which means the data in it is the pure bitstream instead of having Intel FPGA own header and etc. However, some of the IP available in Cyclone 10 LP might not supported in cyclone IV. In that case, you should generate the RBF with the SOF compiled from Cyclone IV.