BUS_ADDR_LO
AE_WRITE_4(sc, AE_RXD_ADDR_LO_REG, BUS_ADDR_LO(addr));
AE_WRITE_4(sc, AE_TXD_ADDR_LO_REG, BUS_ADDR_LO(addr));
AE_WRITE_4(sc, AE_TXS_ADDR_LO_REG, BUS_ADDR_LO(addr));