UARTCR1
cr1 = readb(port->membase + UARTCR1);
cr1 = readb(port->membase + UARTCR1);
writeb(cr1, port->membase + UARTCR1);
cr1 = old_cr1 = readb(port->membase + UARTCR1);
writeb(cr1, port->membase + UARTCR1);
cr = readb(sport->port.membase + UARTCR1);