Hi
According to this answer we decided to use eTSEC1 in MII and eTsec3 in RGMII mode but connect both L1VDD and LVDD to 2.5v and manage possible MII problems with timing barriers of course another side of this MII interace is supporting 2.5v.
But we have another problem with some sentences in AN4878 table 31 that "When eTSEC 1 or eTSEC 2 are configured as MII mode some of the MII 1 and MII 2 signals are muxed with eTSEC3 signals. In the RCW configuration eTSEC 3 must be selected as MII" .
does it mean that RCW[EC3] can not be set 000 when we use eTSEC1 in MII? It should be said that MII optional pins not used in our design.
Refer to table 4-14 of LS1021RM we want to set RCW[EC1]=011(MII) and RCW[EC3]=000(RGMII). this doesn't cause any conflict in register settings. May we assume it is possible?
Best Regards
Noghteh
EC3 must be 011 for MII support.