CDNC_UART_MODEM_CTRL_REG_RTS
CDNC_UART_MODEM_CTRL_REG_RTS);
~(CDNC_UART_MODEM_CTRL_REG_DTR | CDNC_UART_MODEM_CTRL_REG_RTS);
modem_ctrl |= CDNC_UART_MODEM_CTRL_REG_RTS;
modem_ctrl |= CDNC_UART_MODEM_CTRL_REG_RTS;
modem_ctrl &= ~CDNC_UART_MODEM_CTRL_REG_RTS;