P_MII_DUPLEX_M
mask = P_MII_DUPLEX_M | masks[P_MII_TX_FLOW_CTRL] |
val = FIELD_PREP(P_MII_DUPLEX_M, bitval[P_MII_FULL_DUPLEX]);
val = FIELD_PREP(P_MII_DUPLEX_M, bitval[P_MII_HALF_DUPLEX]);