UARTCR2_RE
cr2 &= ~UARTCR2_RE;
cr2 |= UARTCR2_RE;
UARTCR2_RIE | UARTCR2_RE);
cr2 |= UARTCR2_RIE | UARTCR2_RE | UARTCR2_TE;
cr2 &= ~(UARTCR2_TE | UARTCR2_RE |
writeb(old_cr2 & ~(UARTCR2_TE | UARTCR2_RE),
cr2 |= UARTCR2_TE | UARTCR2_RE;
cr &= UARTCR2_TE | UARTCR2_RE;
writeb(cr2 & ~UARTCR2_RE, port->membase + UARTCR2);
writeb(UARTCR2_RE | UARTCR2_TE, port->membase + UARTCR2);