The implementation scripts for the following cores do not generate a bitstream when the target device is Spartan-3E:
- Gigabit Ethernet MAC v6.0
- Tri-mode Ethernet MAC v2.1
- Ethernet 1000BASE-X PCS/PMA or SGMII v6.0
- Ethernet Statistics v1.1
- GFP v1.3
At the time of the IP Update #1 release, only Spartan-3E ES silicon is available. Spartan-3E ES devices requires specific BitGen settings to create the bitstreams, and it is the only type of bitstream that can currently (ISE 7.1i Service Pack 2) be generated. For more information on generating Spartan-3E ES bitstreams and when ISE will support the generation of production bitstreams, refer to (Xilinx Answer 21023).
When production devices become available and the ISE tools support bitstream generation for them, you can generate a bitstream with the sample implement script by uncommenting the following line:
uncomment: "rem bitgen -w routed"
uncomment: "# bitgen -w routed"