rp2_rmw_set
rp2_rmw_set(port_to_up(port), RP2_TXRX_CTL, RP2_TXRX_CTL_TXIRQ_m);
rp2_rmw_set(port_to_up(port), RP2_TXRX_CTL, RP2_TXRX_CTL_MSRIRQ_m);
rp2_rmw_set(up, RP2_UART_CTL,
rp2_rmw_set(up, RP2_TXRX_CTL,