pub fn into_async(mut self) -> UsbSerialJtag<'d, Async> {
        self.set_interrupt_handler(async_interrupt_handler);

        UsbSerialJtag {
            rx: UsbSerialJtagRx {
                peripheral: self.rx.peripheral,
                phantom: PhantomData,
            },
            tx: UsbSerialJtagTx {
                peripheral: self.tx.peripheral,
                phantom: PhantomData,
            },
        }
    }
Reconfigure the USB Serial JTAG peripheral to operate in asynchronous
mode.
esp-hal/src/usb_serial_jtag.rs