How to programm a Lattice board?
After working around, I finaly find out how. Synplify Pro is the synthetize but you don't need to open it. In Diamond, you see this panel when you are in the workspace:


Click on the second tab "Process", in my case it was hidden from my screen resolution

The following window will open and as you can see there is the ouput file generator. In my case, the bitstream wasn't generate because of Map design problem,but there you go guys. Also you can either use JEDEC or bitstream file as input for the programmer.