DL_READ_WORD
if (DL_READ_WORD(DL_UBA_RCSR) & DL_RCSR_RX_DONE) {
c = DL_READ_WORD(DL_UBA_RBUF);
if (DL_READ_WORD(DL_UBA_XCSR) & DL_XCSR_TX_READY) {
DL_WRITE_WORD(DL_UBA_XCSR, DL_READ_WORD(DL_UBA_XCSR) |
DL_WRITE_WORD(DL_UBA_XCSR, DL_READ_WORD(DL_UBA_XCSR) &