LCR_SBREAK
reg |= LCR_SBREAK;
reg &= ~LCR_SBREAK;
lcr = ISSET(sc->sc_lcr, LCR_SBREAK) | cflag2lcr(t->c_cflag);
lcr = ISSET(sc->sc_lcr, LCR_SBREAK) | cflag2lcr(t->c_cflag);
SET(sc->sc_lcr, LCR_SBREAK);
CLR(sc->sc_lcr, LCR_SBREAK);
lcr = ISSET(sc->sc_lcr, LCR_SBREAK) | cflag2lcr(t->c_cflag);