Hello Champs,
Due to the board size limitation, customer used only 1 PHY chip to save the space. He designed his own board shown in below block diagram. C6678 1 device can connect to PHY successfully. But C6678 0 can't connect to the PHY. 
1. Is the above daisy chain design feasible?
2. If it is feasible, how to configure the SWITCH to get it work?
3. If it is not feasible, is some other method to connect the C6678 0 to the PHY?
Thanks.
Rgds
Shine
Shine,
Yes, the daisy chain shown is feasible. This has been implemented by other customers. The CPSW supports wire-rate packet forwarding. The KeyStone Architecture Gigabit Ethernet (GbE) Switch Subsystem User's Guide (SPRUGV9D) at 
provides guidance. Please refer to section 2.3.6 Address Lookup Engine (ALE) Submodule Architecture for guidance setting up the ALE for packet forwarding. I will check whether we provide example software that demonstrates this capability.
Tom
