UARTMODEM
u8 modem = readb(port->membase + UARTMODEM) &
writeb(modem, port->membase + UARTMODEM);
writeb(modem, port->membase + UARTMODEM);
modem = readb(port->membase + UARTMODEM);
writeb(modem, port->membase + UARTMODEM);