OWL_UART_CTL_TXIE
val &= ~(OWL_UART_CTL_TXIE | OWL_UART_CTL_TXDE);
val |= OWL_UART_CTL_TXIE;
val &= ~(OWL_UART_CTL_TXIE | OWL_UART_CTL_RXIE
val |= OWL_UART_CTL_RXIE | OWL_UART_CTL_TXIE;
val &= ~(OWL_UART_CTL_RXIE | OWL_UART_CTL_TXIE);