DW_IATU_LWR_TARGET_ADDR
DBI_WR4(sc, DW_IATU_LWR_TARGET_ADDR, 0x12340000);
reg = DBI_RD4(sc, DW_IATU_LWR_TARGET_ADDR);
DBI_WR4(sc, DW_IATU_LWR_TARGET_ADDR, pci_addr & 0xFFFFFFFF);