[参考译文] TM4C123FH6PM：USB 复合器件：TX 不适用于从3开始的 CDC 复合器件

您好 Oleg、

这里没有足够的信息让我真正评估这一点。 您能否提供整个 USB_structs.c 和 usb_structs.h 文件作为附件、以便我可以查看所有声明和定义的变量？

我 非常相信您可以完成3个以上的端口、但 我不确定上限是多少、我肯定没有看到使用的端口数量减少了8个16个。 如果不修改 USB 库、我怀疑16位可能会是可行的。

此致、

Ralph Jacobi

问题从第4个 CDC 器件开始。 3个器件运行良好。 外部变量 nPorts 定义活动 CDC 器件的数量。 我 的所有 USB 部件代码都位于 usb.c 文件中、这里是：

/*
 * usb.c
 *
 *  Created on: 8 ёхэЄ. 2021 у.
 *      Author: Kit
 */

#include <stdbool.h>
#include <stdint.h>
#include "inc/hw_ints.h"
#include "inc/hw_memmap.h"
#include "inc/hw_types.h"
#include "inc/hw_uart.h"
#include "inc/hw_qei.h"
#include "inc/hw_i2c.h"
#include "inc/hw_can.h"
#include "driverlib/debug.h"
#include "driverlib/gpio.h"
#include "driverlib/interrupt.h"
#include "driverlib/rom.h"
#include "driverlib/rom_map.h"
#include "driverlib/sysctl.h"
#include "driverlib/systick.h"
#include "driverlib/timer.h"
#include "driverlib/uart.h"
#include "driverlib/usb.h"
#include "driverlib/gpio.h"
#include "driverlib/i2c.h"
#include "driverlib/qei.h"
#include "driverlib/pin_map.h"
#include "driverlib/can.h"
#include "usblib/usblib.h"
#include "usblib/usbcdc.h"
#include "usblib/usbhid.h"
#include "usblib/usb-ids.h"
#include "usblib/device/usbdevice.h"
#include "usblib/device/usbdcomp.h"
#include "usblib/device/usbdcdc.h"
#include "usblib/device/usbdhid.h"
#include "usblib/device/usbdhidkeyb.h"


//*****************************************************************************
//
// The languages supported by this device.
//
//*****************************************************************************
const uint8_t g_pui8LangDescriptor[] =
{
    4,
    USB_DTYPE_STRING,
    USBShort(USB_LANG_EN_US)
};

//*****************************************************************************
//
// The manufacturer string.
//
//*****************************************************************************
const uint8_t g_pui8ManufacturerString[] =
{
    (17 + 1) * 2,
    USB_DTYPE_STRING,
    'T', 0, 'e', 0, 'x', 0, 'a', 0, 's', 0, ' ', 0, 'I', 0, 'n', 0, 's', 0,
    't', 0, 'r', 0, 'u', 0, 'm', 0, 'e', 0, 'n', 0, 't', 0, 's', 0,
};

//*****************************************************************************
//
// The product string.
//
//*****************************************************************************
const uint8_t g_pui8ProductString[] =
{
    2 + (16 * 2),
    USB_DTYPE_STRING,
    'V', 0, 'i', 0, 'r', 0, 't', 0, 'u', 0, 'a', 0, 'l', 0, ' ', 0,
    'C', 0, 'O', 0, 'M', 0, ' ', 0, 'P', 0, 'o', 0, 'r', 0, 't', 0
};
const uint8_t g_pui8ProductStringComp[] =
{
    2 + (16 * 2),
    USB_DTYPE_STRING,
    'P', 0, 'o', 0, 'r', 0, 't', 0, 'l', 0, 'a', 0, 'b', 0, ' ', 0,
    'B', 0, 'r', 0, 'e', 0, 'a', 0, 'k', 0, 'o', 0, 'u', 0, 't', 0
};

uint8_t g_pui8SerialNumberStringComp[] =
{
    2 + (8 * 2),
    USB_DTYPE_STRING,
    '0', 0, '0', 0, '0', 0, '0', 0, '0', 0, '0', 0, '0', 0, '1', 0
};

//*****************************************************************************
//
// The control interface description string.
//
//*****************************************************************************
const uint8_t g_pui8ControlInterfaceString[] =
{
    2 + (21 * 2),
    USB_DTYPE_STRING,
    'A', 0, 'C', 0, 'M', 0, ' ', 0, 'C', 0, 'o', 0, 'n', 0, 't', 0,
    'r', 0, 'o', 0, 'l', 0, ' ', 0, 'I', 0, 'n', 0, 't', 0, 'e', 0,
    'r', 0, 'f', 0, 'a', 0, 'c', 0, 'e', 0
};

//*****************************************************************************
//
// The configuration description string.
//
//*****************************************************************************
const uint8_t g_pui8ConfigString[] =
{
 2 + (26 * 2),
 USB_DTYPE_STRING,
 'B', 0, 'u', 0, 's', 0, ' ', 0, 'P', 0, 'o', 0, 'w', 0,
 'e', 0, 'r', 0, 'e', 0, 'd', 0, ' ', 0, 'C', 0, 'o', 0, 'n', 0,
 'f', 0, 'i', 0, 'g', 0, 'u', 0, 'r', 0, 'a', 0, 't', 0, 'i', 0,
 'o', 0, 'n', 0
};
const uint8_t g_pui8ConfigStringComp[] =
{
    2 + (26 * 2),
    USB_DTYPE_STRING,
    'B', 0, 'u', 0, 's', 0, ' ', 0, 'P', 0, 'o', 0, 'w', 0,
    'e', 0, 'r', 0, 'e', 0, 'd', 0, ' ', 0, 'C', 0, 'o', 0, 'n', 0,
    'f', 0, 'i', 0, 'g', 0, 'u', 0, 'r', 0, 'a', 0, 't', 0, 'i', 0,
    'o', 0, 'n', 0
};

//*****************************************************************************
//
// The descriptor string table.
//
//*****************************************************************************
const uint8_t * const g_pui8StringDescriptorsCDC[] =
{
    g_pui8LangDescriptor,
    g_pui8ManufacturerString,
    g_pui8ProductString,
    g_pui8SerialNumberStringComp,
    g_pui8ControlInterfaceString,
    g_pui8ConfigString
};

const uint8_t * const g_pui8StringDescriptorsComp[] =
{
    g_pui8LangDescriptor,
    g_pui8ManufacturerString,
    g_pui8ProductStringComp,
    g_pui8SerialNumberStringComp,
    g_pui8ControlInterfaceString,
    g_pui8ConfigStringComp
};

#define NUM_STRING_DESCRIPTORS (sizeof(g_pui8StringDescriptorsCDC) /             \
                                sizeof(uint8_t *))
#define NUM_STRING_DESCRIPTORS_COMP (sizeof(g_pui8StringDescriptorsComp) /             \
                                sizeof(uint8_t *))

#define MAX_SERIAL_DEVICES      16
#define UART_BUFFER_SIZE        256

extern tUSBBuffer g_psTxBuffer[MAX_SERIAL_DEVICES];
extern tUSBBuffer g_psRxBuffer[MAX_SERIAL_DEVICES];
extern tUSBDCDCDevice g_psCDCDevice[MAX_SERIAL_DEVICES];
extern uint8_t g_pui8USBTxBuffer[];
extern uint8_t g_pui8USBRxBuffer[];
extern uint32_t ControlHandler(void *pvCBData, uint32_t ui32Event,
                               uint32_t ui32MsgValue, void *pvMsgData);
extern uint32_t RxHandlerCDC(void *pvCBData, uint32_t ui32Event,
                              uint32_t ui32MsgValue, void *pvMsgData);
extern uint32_t TxHandlerCDC(void *pvlCBData, uint32_t ui32Event,
                              uint32_t ui32MsgValue, void *pvMsgData);


#define CDC_DEV_STRUCT(n)                           \
        {                                           \
            USB_VID_TI_1CBE,                        \
            USB_PID_SERIAL,                         \
            0,                                      \
            USB_CONF_ATTR_BUS_PWR,                  \
            ControlHandler,                         \
            (void *)&g_psCDCDevice[n],              \
            USBBufferEventCallback,                 \
            (void *)&g_psRxBuffer[n],               \
            USBBufferEventCallback,                 \
            (void *)&g_psTxBuffer[n],               \
            g_pui8StringDescriptorsCDC,             \
            NUM_STRING_DESCRIPTORS                  \
        }

tUSBDCDCDevice g_psCDCDevice[MAX_SERIAL_DEVICES] =
{
 CDC_DEV_STRUCT(0),
 CDC_DEV_STRUCT(1),
 CDC_DEV_STRUCT(2),
 CDC_DEV_STRUCT(3),
 CDC_DEV_STRUCT(4),
 CDC_DEV_STRUCT(5),
 CDC_DEV_STRUCT(6),
 CDC_DEV_STRUCT(7),
 CDC_DEV_STRUCT(8),
 CDC_DEV_STRUCT(9),
 CDC_DEV_STRUCT(10),
 CDC_DEV_STRUCT(11),
 CDC_DEV_STRUCT(12),
 CDC_DEV_STRUCT(13),
 CDC_DEV_STRUCT(14),
 CDC_DEV_STRUCT(15)
};

#define CDC_RX_BUFFER(n)                            \
        {                                           \
            false,                                  \
            RxHandlerCDC,                           \
            (void *)&g_psCDCDevice[n],              \
            USBDCDCPacketRead,                      \
            USBDCDCRxPacketAvailable,               \
            (void *)&g_psCDCDevice[n],              \
            g_ppui8USBRxBuffer[n],                  \
            UART_BUFFER_SIZE,                       \
        }

uint8_t g_ppui8USBRxBuffer[MAX_SERIAL_DEVICES][UART_BUFFER_SIZE];
tUSBBuffer g_psRxBuffer[MAX_SERIAL_DEVICES] =
{
 CDC_RX_BUFFER(0),
 CDC_RX_BUFFER(1),
 CDC_RX_BUFFER(2),
 CDC_RX_BUFFER(3),
 CDC_RX_BUFFER(4),
 CDC_RX_BUFFER(5),
 CDC_RX_BUFFER(6),
 CDC_RX_BUFFER(7),
 CDC_RX_BUFFER(8),
 CDC_RX_BUFFER(9),
 CDC_RX_BUFFER(10),
 CDC_RX_BUFFER(11),
 CDC_RX_BUFFER(12),
 CDC_RX_BUFFER(13),
 CDC_RX_BUFFER(14),
 CDC_RX_BUFFER(15)
};

#define CDC_TX_BUFFER(n)                            \
        {                                           \
            true,                                   \
            TxHandlerCDC,                           \
            (void *)&g_psCDCDevice[n],              \
            USBDCDCPacketWrite,                     \
            USBDCDCTxPacketAvailable,               \
            (void *)&g_psCDCDevice[n],              \
            g_ppcUSBTxBuffer[n],                    \
            UART_BUFFER_SIZE,                       \
        }

uint8_t g_ppcUSBTxBuffer[MAX_SERIAL_DEVICES][UART_BUFFER_SIZE];
tUSBBuffer g_psTxBuffer[MAX_SERIAL_DEVICES] =
{
 CDC_TX_BUFFER(0),
 CDC_TX_BUFFER(1),
 CDC_TX_BUFFER(2),
 CDC_TX_BUFFER(3),
 CDC_TX_BUFFER(4),
 CDC_TX_BUFFER(5),
 CDC_TX_BUFFER(6),
 CDC_TX_BUFFER(7),
 CDC_TX_BUFFER(8),
 CDC_TX_BUFFER(9),
 CDC_TX_BUFFER(10),
 CDC_TX_BUFFER(11),
 CDC_TX_BUFFER(12),
 CDC_TX_BUFFER(13),
 CDC_TX_BUFFER(14),
 CDC_TX_BUFFER(15)
};

#define DESCRIPTOR_DATA_SIZE    (COMPOSITE_DCDC_SIZE * MAX_SERIAL_DEVICES)

//****************************************************************************
//
// The memory allocated to hold the composite descriptor that is created by
// the call to USBDCompositeInit().
//
//****************************************************************************
uint8_t g_pui8DescriptorData[DESCRIPTOR_DATA_SIZE];

tCompositeEntry g_psCompEntries[MAX_SERIAL_DEVICES];

//*****************************************************************************
//
//! The structure used by the application to define operating parameters for
//! the composite device class.
//
//*****************************************************************************
typedef struct
{
    //
    //! The vendor ID that this device is to present in the device descriptor.
    //
    const uint16_t ui16VID;

    //
    //! The product ID that this device is to present in the device descriptor.
    //
    const uint16_t ui16PID;

    //
    //! The maximum power consumption of the device, expressed in mA.
    //
    const uint16_t ui16MaxPowermA;

    //
    //! Indicates whether the device is self or bus-powered and whether or not
    //! it supports remote wake up.  Valid values are \b USB_CONF_ATTR_SELF_PWR
    //! or \b USB_CONF_ATTR_BUS_PWR, optionally ORed with
    //! \b USB_CONF_ATTR_RWAKE.
    //
    const uint8_t ui8PwrAttributes;

    //
    //! A pointer to the callback function which will be called to notify
    //! the application of events relating to the operation of the composite
    //! device.
    //
    const tUSBCallback pfnCallback;

    //
    //! A pointer to the string descriptor array for this device.  This array
    //! must contain the following string descriptor pointers in this order.
    //! Language descriptor, Manufacturer name string (language 1), Product
    //! name string (language 1), Serial number string (language 1), Composite
    //! device interface description string (language 1), Configuration
    //! description string (language 1).
    //!
    //! If supporting more than 1 language, the descriptor block (except for
    //! string descriptor 0) must be repeated for each language defined in the
    //! language descriptor.
    //!
    //
    const uint8_t * const *ppui8StringDescriptors;

    //
    //! The number of descriptors provided in the ppStringDescriptors
    //! array.  This must be 1 + ((5 + (number of strings)) *
    //!                           (number of languages)).
    //
    const uint32_t ui32NumStringDescriptors;

    //
    //! The number of devices in the psDevices array.
    //
    uint32_t ui32NumDevices;

    //
    //! This application supplied array holds the the top level device class
    //! information as well as the Instance data for that class.
    //
    tCompositeEntry * const psDevices;

    //
    //! The private data for this device instance.  This memory must remain
    //! accessible for as long as the composite device is in use and must
    //! not be modified by any code outside the composite class driver.
    //
    tCompositeInstance sPrivateData;
}
tUSBDCompositeDeviceM;

//****************************************************************************
//
// Allocate the Device Data for the top level composite device class.
//
//****************************************************************************
tUSBDCompositeDeviceM g_sCompDevice =
{
    //
    // Stellaris VID.
    //
    USB_VID_TI_1CBE,

    //
    // Stellaris PID for composite serial device.
    //
    USB_PID_COMP_HID_SER,

    //
    // This is in 2mA increments so 500mA.
    //
    250,

    //
    // Bus powered device.
    //
    USB_CONF_ATTR_BUS_PWR,

    //
    // There is no need for a default composite event handler.
    //
    0,

    //
    // The string table.
    //
    g_pui8StringDescriptorsComp,
    NUM_STRING_DESCRIPTORS_COMP,

    //
    // The Composite device array.
    //
    0,                                                          // To be changed on reinit
    g_psCompEntries
};

bool bConnected[16] = {false, false, false, false, false, false, false, false,
                       false, false, false, false, false, false, false, false};

int nPorts = 1;

uint32_t
ControlHandler(void *pvCBData, uint32_t ui32Event,
               uint32_t ui32MsgValue, void *pvMsgData)
{
    tUSBDCDCDevice *pDev = (tUSBDCDCDevice *)pvCBData;
    uint8_t nPort = (((uint8_t *)pDev) - ((uint8_t *)g_psCDCDevice)) / sizeof(tUSBDCDCDevice);
    switch(ui32Event)
    {
        //
        // We are connected to a host and communication is now possible.
        //
        case USB_EVENT_CONNECTED:
        {
            int i;
            for(i = 0; i < nPorts; i++)
            {
                bConnected[i] = true;
                //
                // Flush our buffers.
                //
                USBBufferFlush(&g_psTxBuffer[i]);
                USBBufferFlush(&g_psRxBuffer[i]);
            }

            break;
        }

        //
        // The host has disconnected.
        //
        case USB_EVENT_DISCONNECTED:
        {
            bConnected[nPort] = false;
            break;
        }

        //
        // Return the current serial communication parameters.
        //
        case USBD_CDC_EVENT_GET_LINE_CODING:
        {
            {
                tLineCoding *psLineCoding = (tLineCoding *)pvMsgData;
                psLineCoding->ui32Rate = 19200;
                psLineCoding->ui8Databits = 8;
                psLineCoding->ui8Parity = USB_CDC_PARITY_NONE;
                psLineCoding->ui8Stop = USB_CDC_STOP_BITS_1;
            }
            break;
        }

        //
        // Set the current serial communication parameters.
        //
        case USBD_CDC_EVENT_SET_LINE_CODING:
        {
            /*{
                tLineCoding *psLineCoding = (tLineCoding *)pvMsgData;
                BaudRate = psLineCoding->ui32Rate;
            }*/
            break;
        }

        //
        // Set the current serial communication parameters.
        //
        case USBD_CDC_EVENT_SET_CONTROL_LINE_STATE:
        {
            /*if(((unsigned short)ui32MsgValue) == 0)
                RTSPaused[Port] = true;
            if(((unsigned short)ui32MsgValue) == 1)
                RTSPaused[Port] = false;
            if(((unsigned short)ui32MsgValue) == 2)
                RTSPaused[Port] = true;
            if(((unsigned short)ui32MsgValue) == 3)
                RTSPaused[Port] = false;*/
            // TODO: control lines
            break;
        }

        //
        // Send a break condition on the serial line.
        //
        case USBD_CDC_EVENT_SEND_BREAK:
        {
            //SendBreak(true);
            break;
        }

        //
        // Clear the break condition on the serial line.
        //
        case USBD_CDC_EVENT_CLEAR_BREAK:
        {
            //SendBreak(false);
            break;
        }

        //
        // Ignore SUSPEND and RESUME for now.
        //
        case USB_EVENT_SUSPEND:
        case USB_EVENT_RESUME:
        {
            break;
        }

        //
        // We don't expect to receive any other events.  Ignore any that show
        // up in a release build or hang in a debug build.
        //
        default:
        {
            break;
        }
    }

    return(0);

}

void SendCAN(uint8_t nPort, uint8_t *Data, uint8_t Len);

uint32_t RxHandlerCDC(void *pvCBData, uint32_t ui32Event,
                              uint32_t ui32MsgValue, void *pvMsgData)
{
    tUSBDCDCDevice *pDev = (tUSBDCDCDevice *)pvCBData;
    uint8_t nPort = (((uint8_t *)pDev) - ((uint8_t *)g_psCDCDevice)) / sizeof(tUSBDCDCDevice);
    //
    // Which event are we being sent?
    //
    switch(ui32Event)
    {
        //
        // A new packet has been received.
        //
        case USB_EVENT_RX_AVAILABLE:
        {
            uint32_t DataRead = 0;
            uint8_t Data[64];
            while((DataRead = USBBufferRead(g_psRxBuffer + nPort, Data, 64)) != 0)
            {
                SendCAN(nPort, Data, DataRead);
            }
            break;
        }

        //
        // We are being asked how much unprocessed data we have still to
        // process. We return 0 if the UART is currently idle or 1 if it is
        // in the process of transmitting something. The actual number of
        // bytes in the UART FIFO is not important here, merely whether or
        // not everything previously sent to us has been transmitted.
        //
        case USB_EVENT_DATA_REMAINING:
        {
            return CANStatusGet(CAN0_BASE, CAN_STS_TXREQUEST) & (1 << (nPort + 1)) ? 1 : 0;
        }

        //
        // We are being asked to provide a buffer into which the next packet
        // can be read. We do not support this mode of receiving data so let
        // the driver know by returning 0. The CDC driver should not be
        // sending this message but this is included just for illustration and
        // completeness.
        //
        case USB_EVENT_REQUEST_BUFFER:
        {
            return(0);
        }

        //
        // We don't expect to receive any other events.  Ignore any that show
        // up in a release build or hang in a debug build.
        //
        default:
        {
            break;
        }
    }

    return(0);
}

uint32_t TxHandlerCDC(void *pvlCBData, uint32_t ui32Event,
                              uint32_t ui32MsgValue, void *pvMsgData)
{
    tUSBDCDCDevice *pDev = (tUSBDCDCDevice *)pvlCBData;
    uint8_t nPort = (((uint8_t *)pDev) - ((uint8_t *)g_psCDCDevice)) / sizeof(tUSBDCDCDevice);
    return(0);
}

void USBSend(uint8_t nPort, uint8_t *Data, uint8_t Len)
{
    if(bConnected[nPort])
        USBBufferWrite((tUSBBuffer *)&g_psTxBuffer[nPort], Data, Len);
}

void *pCompInst = 0;
uint8_t g_pucDescriptorData[DESCRIPTOR_DATA_SIZE];

void ReinitUSB()
{
    if(pCompInst)
    {
        USBDCompositeTerm(pCompInst);
        SysCtlPeripheralDisable(SYSCTL_PERIPH_USB0);
        SysCtlDelay(80000000);
        SysCtlPeripheralEnable(SYSCTL_PERIPH_USB0);
        uint32_t Clk = SysCtlClockGet();
        uint32_t Power = USBLIB_FEATURE_POWER_BUS;
        USBDCDFeatureSet(0, USBLIB_FEATURE_CPUCLK, &Clk);
        USBDCDFeatureSet(0, USBLIB_FEATURE_POWER, &Power);
        USBStackModeSet(0, eUSBModeForceDevice, 0);
    }
    int i;
    for(i = 0; i < nPorts; i++)
    {
        g_sCompDevice.psDevices[i].pvInstance =
                USBDCDCCompositeInit(0, &g_psCDCDevice[i], &g_psCompEntries[i]);
        USBBufferInit(&g_psTxBuffer[i]);
        USBBufferInit(&g_psRxBuffer[i]);
    }
    g_sCompDevice.ui32NumDevices = nPorts;
    pCompInst = USBDCompositeInit(0, (tUSBDCompositeDevice *)&g_sCompDevice, COMPOSITE_DCDC_SIZE * nPorts,
                      g_pucDescriptorData);
}

int InitCtr = 0;

void TimersInt()
{
    TimerIntClear(TIMER1_BASE, TIMER_TIMA_TIMEOUT);
    if(InitCtr++ == 5)
    {
        ReinitUSB();
        TimerDisable(TIMER1_BASE, TIMER_A);
    }
}

void InitUSB()
{
    SysCtlPeripheralEnable(SYSCTL_PERIPH_USB0);
    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOD);
    GPIOPinTypeUSBAnalog(GPIO_PORTD_BASE, GPIO_PIN_5 | GPIO_PIN_4);
    uint32_t Clk = SysCtlClockGet();
    uint32_t Power = USBLIB_FEATURE_POWER_BUS;
    USBDCDFeatureSet(0, USBLIB_FEATURE_CPUCLK, &Clk);
    USBDCDFeatureSet(0, USBLIB_FEATURE_POWER, &Power);
    USBStackModeSet(0, eUSBModeForceDevice, 0);

    SysCtlPeripheralEnable(SYSCTL_PERIPH_TIMER1);
    TimerConfigure(TIMER1_BASE, TIMER_CFG_PERIODIC);
    TimerLoadSet(TIMER1_BASE, TIMER_A, SysCtlClockGet());
    TimerIntRegister(TIMER1_BASE, TIMER_A, &TimersInt);
    TimerIntEnable(TIMER1_BASE, TIMER_TIMA_TIMEOUT);
    TimerEnable(TIMER1_BASE, TIMER_A);

}

您好 Oleg、

感谢您提供代码。

那么、我的理解是、应用程序将 nPorts 设置为等于某个值、如果您设置 nPorts = 3并调用 ReinitUSB、那么它可以正常工作、但是如果您设置 nPorts = 4并调用 ReinitUSB、那么您只能获得三个 CDC 接口？

虽然我没有像设置代码那样使用您放置的代码、但我确实将其移植到项目中并进行测试、并且 我能够获得最多7个枚举端口。 在这里、最初不清楚这是否是 USB 库的限制、但我确实能够获得4、5、6和7个 CDC 端口来正确枚举。

有关尝试使用7个以上端口的进一步调查需要几天时间、因为我需要深入研究 USB 分析仪捕获、以了解7个端口和8个端口之间的区别、以查看其是否是库限制或其他内容。

此致、

Ralph Jacobi

错误。 在启动5秒后调用一次 ReinitUSB，这次将 nPorts 设置为正确的值。 所有 CDC 端口都已设置并显示在 Windows 设备管理器中、我可以连接它们。 但是、当我连接任何大于第三方的端口时、我可以将数据写入该端口、并且我可以接收器件上的所有数据、但当器件将数据写回主机时、主机不会接收到数据、 并且端口的 iCDCTxState 字段会 永远设置为 eCDCStateWaitData。

我找到了原因。

每个使用的 CDC 端口有2个输入端点、一个中断和一个批量。

由于最多有7个端点、因此第4个器件超出端点。

是否有任何可能的解决方法？

您好 Oleg、

很高兴您找到了权变措施。  我认为这是一个根本原因和一个变通办法。 很抱歉、我一开始不太了解核心问题。 通常、在涉及复合材料时、其他器件的枚举存在问题、这是我最初关注的问题、但我看到您更关注数据传输元素。

7个端点限制也是允许最多连接7个器件的原因、这也说明了这一点。 老实说、我以前没有考虑过硬件限制、也没有昨天的软件那样。

此致、

Ralph Jacobi