I am trying to use NE64 inbuilt ethernet at bus clock 16MHz. I have a TCP/IP stack working at 25MHz bus clock and internal flash. But if i reduce the busclock to 16Mhz and set MDCSEL to generate MDC freq less than 2.5MHz, stuff does not work. Ultimately i want to use external RAM and ethernet at 16MHz later. Am I missing any other configuration needed to be modified? Any one had done EMAC workign at 16MHz bus clock? pls help me out.