/**
 * (c) 2026, Micro:bit Educational Foundation and contributors
 *
 * Derived from dapjs (https://github.com/ARMmbed/dapjs) which is
 * Copyright (c) Arm Limited 2018
 * Copyright (c) Microsoft Corporation
 *
 * SPDX-License-Identifier: MIT
 *
 * See arm-debug.ts for the full dapjs license.
 *
 * WebUSB transport layer. Handles opening/closing the USB interface,
 * finding the correct CMSIS-DAP endpoints, and reading/writing raw packets.
 *
 * This is the lowest layer in the USB stack, sitting beneath the CMSIS-DAP
 * protocol layer. It knows nothing about DAP commands — it just moves
 * fixed-size packets between the host and the USB device.
 *
 * micro:bit V2 uses CMSIS-DAP v2 (bulk endpoints). micro:bit V1 uses
 * CMSIS-DAP v1 (HID) which has no bulk endpoints — we fall back to
 * control transfers (SET_REPORT/GET_REPORT) in that case.
 */
export declare const PACKET_SIZE = 64;
export interface Transport {
    readonly isOpen: boolean;
    open(): Promise<void>;
    close(): Promise<void>;
    read(): Promise<DataView>;
    write(data: Uint8Array): Promise<void>;
}
export declare class UsbTransport implements Transport {
    private device;
    private interfaceNumber?;
    private endpointIn?;
    private endpointOut?;
    constructor(device: USBDevice);
    get isOpen(): boolean;
    open(): Promise<void>;
    close(): Promise<void>;
    read(): Promise<DataView>;
    write(data: Uint8Array): Promise<void>;
}