In my design that uses loc'ing of the location of the EMACs and the PPCs, or uses multiple PPCs and EMACs, the following Place error occurs:
"ERROR:Place:580 - Placer was unable to create RPM for the PPC405 component
CPUCPLX/ppc405_1/ppc405_1/PPC405_ADV_i and EMAC component
connected by the DCREMACENABLE pin on the EMAC component"
The error is caused by an incorrect RPM check in Place. You can work around this issue by connecting the DCREMACENABLER signal from the PPC to the DCREMACENABLE signal on the hard EMAC.