IER_ETXRDY
if (ISSET(sc->sc_ier, IER_ETXRDY))
sc->sc_ier = IER_ETXRDY | IER_ERXRDY;
c = sc->sc_ier | IER_ETXRDY;
sc->sc_ier &= ~IER_ETXRDY;
if (!ISSET(sc->sc_ier, IER_ETXRDY)) {
SET(sc->sc_ier, IER_ETXRDY);
if (ISSET(sc->sc_ier, IER_ETXRDY)) {
CLR(sc->sc_ier, IER_ETXRDY);
if (com1_dev.regs.ier & IER_ETXRDY) {
if (com1_dev.regs.ier & IER_ETXRDY)