what's the difference between cyclnone II and cyclnone III device?

[Altera_Forum]

I have designed a simple risc cpu contained sram and rom ip which generated by MegaWizard,then I compiled this project under the cyclone II EP2C5 device and download the config flie to EP2C5 device,it works right.But when I using cyclone III EP3C25 device and download the config flie to EP3C25 device ,it not work,what's wrong?anyboby can help me?thanks reply.

[Altera_Forum]

You need to recompile your project for a EP3C25.

[Altera_Forum]

Correct, you need to recompile this project as the FPGA is a different device so the target has changed. 

 also notice that cyclone II devices have M4K memory blocks, and cyclone III have M9K memory blocks. so you should check if you use these memory blocks and have set them correctly or (thats mostly better) have set the memory type to AUTO so quartus will use the correct memory type. for example if you use the wizzard to create on chip memory for example 2kByte (2048x8) the cyclone II fpga will use 4 M4K blocks whereas cyclone III will use 2 M9K memory blocks

[Altera_Forum]

sure,I have recompiled the project and also regenerated the same size of rom and ram which using M9K memery block and replaced the old ram and rom,and then I make a timing simulation under quartus II 7.2,the simulation result is right.after config it still not works correctly.I am sure the hardware has no problem.

[Altera_Forum]

Hi 

 please check you hardware by downloading the some reference design based on Cyclone III from our Altera website,if it works it means that your hardware is working because after full compilation it should work

[Altera_Forum]

To prove hardware is working or not ,I wrote a test code as atatchment provided.after downloading,I can see 4 LEDs flashed from all off to all on one by one,so hardware is working.