Description
In Quartus® II software you will need to target the Stratix® IV GX device part number EP4SGX230FF35C2XES if you have ordered the EP4SGX230FF35C2NES part.
The conflict is due to a limitation in the number of characters that can be used to identify a device. The EP4SGX230FF35 ES device is only available in the -2X speed grade. The part number EP4SGX230FF35C2NES is actually a EP4SGX230FF35C2XNES device, but due to the character limitation the X was dropped in order to incorporate the -N to indicate a lead free device.