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USB转双串口，核心技术就在于组合设备（USB Composite）的实现，组合设备的实现，其核心技术在于描述符的实现，下面我们先给出描述符：

设备描述符

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00001 00002 00003 00004 00005 00006 00007 00008 00009 00010 00011 00012 00013 00014 00015 00016 00017 00018 00019 00020 00021 00022 00023 00024 00025 00026 00027

__ALIGN_BEGIN uint8_t USBD_DeviceDesc[USB_SIZ_DEVICE_DESC] __ALIGN_END = { 0x12, /*bLength */ USB_DEVICE_DESCRIPTOR_TYPE, /*bDescriptorType*/ 0x00, /*bcdUSB */ 0x02, #ifdef DUAL_COM 0xEF, /*bDeviceClass*/ 0x02, /*bDeviceSubClass*/ 0x01, /*bDeviceProtocol*/ #else 0x00, /*bDeviceClass*/ 0x00, /*bDeviceSubClass*/ 0x00, /*bDeviceProtocol*/ #endif USB_OTG_MAX_EP0_SIZE, /*bMaxPacketSize*/ LOBYTE(USBD_VID), /*idVendor*/ HIBYTE(USBD_VID), /*idVendor*/ LOBYTE(USBD_PID), /*idVendor*/ HIBYTE(USBD_PID), /*idVendor*/ 0x00, /*bcdDevice rel. 2.00*/ 0x02, USBD_IDX_MFC_STR, /*Index of manufacturer  string*/ USBD_IDX_PRODUCT_STR, /*Index of product string*/ USBD_IDX_SERIAL_STR, /*Index of serial number string*/ USBD_CFG_MAX_NUM /*bNumConfigurations*/ } ; /* USB_DeviceDescriptor */

注意：双串口需要全局定义DUAL_COM宏

配置描述符是重中之重

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00001 00002 00003 00004 00005 00006 00007 00008 00009 00010 00011 00012 00013 00014 00015 00016 00017 00018 00019 00020 00021 00022 00023 00024 00025 00026 00027 00028 00029 00030 00031 00032 00033 00034 00035 00036 00037 00038 00039 00040 00041 00042 00043 00044 00045 00046 00047 00048 00049 00050 00051 00052 00053 00054 00055 00056 00057 00058 00059 00060 00061 00062 00063 00064 00065 00066 00067 00068 00069 00070 00071 00072 00073 00074 00075 00076 00077 00078 00079 00080 00081 00082 00083 00084 00085 00086 00087 00088 00089 00090 00091 00092 00093 00094 00095 00096 00097 00098 00099 00100 00101 00102 00103 00104 00105 00106 00107 00108 00109 00110 00111 00112 00113 00114 00115 00116 00117 00118 00119 00120 00121 00122 00123 00124 00125 00126 00127 00128 00129 00130 00131 00132 00133 00134 00135 00136 00137 00138 00139 00140 00141 00142 00143 00144 00145 00146 00147 00148 00149 00150 00151 00152 00153 00154 00155 00156 00157 00158 00159 00160 00161 00162 00163 00164 00165 00166 00167 00168 00169 00170 00171 00172 00173 00174 00175 00176 00177 00178 00179 00180 00181 00182 00183 00184 00185 00186 00187 00188 00189 00190 00191 00192 00193 00194 00195 00196 00197 00198

__ALIGN_BEGIN uint8_t usbd_cdc_CfgDesc[USB_CDC_CONFIG_DESC_SIZ]  __ALIGN_END = { /*Configuration Descriptor*/ 0x09, /* bLength: Configuration Descriptor size */ USB_CONFIGURATION_DESCRIPTOR_TYPE, /* bDescriptorType: Configuration */ USB_CDC_CONFIG_DESC_SIZ, /* wTotalLength:no of returned bytes */ 0x00, #ifdef DUAL_COM 0x04, /* bNumInterfaces: 4 interface */ #else 0x02, /* bNumInterfaces: 2 interface */ #endif 0x01, /* bConfigurationValue: Configuration value */ 0x00, /* iConfiguration: Index of string descriptor describing the configuration */ 0x60, /* bmAttributes: self powered */ 0xFA, /* MaxPower 0 mA */ /*---------------------------------------------------------------------------*/ #ifdef DUAL_COM // IAD 0x08, // bLength: Interface Descriptor size 0x0B, // bDescriptorType: IAD 0x00, // bFirstInterface 0x02, // bInterfaceCount 0x02, // bFunctionClass: CDC 0x02, // bFunctionSubClass 0x01, // bFunctionProtocol 0x02, // iFunction #endif /*Interface Descriptor */ 0x09, /* bLength: Interface Descriptor size */ USB_INTERFACE_DESCRIPTOR_TYPE, /* bDescriptorType: Interface */ /* Interface descriptor type */ 0x00, /* bInterfaceNumber: Number of Interface */ 0x00, /* bAlternateSetting: Alternate setting */ 0x01, /* bNumEndpoints: One endpoints used */ 0x02, /* bInterfaceClass: Communication Interface Class */ 0x02, /* bInterfaceSubClass: Abstract Control Model */ 0x01, /* bInterfaceProtocol: Common AT commands */ 0x00, /* iInterface: */ /*Header Functional Descriptor*/ 0x05, /* bLength: Endpoint Descriptor size */ 0x24, /* bDescriptorType: CS_INTERFACE */ 0x00, /* bDescriptorSubtype: Header Func Desc */ 0x10, /* bcdCDC: spec release number */ 0x01, /*Call Management Functional Descriptor*/ 0x05, /* bFunctionLength */ 0x24, /* bDescriptorType: CS_INTERFACE */ 0x01, /* bDescriptorSubtype: Call Management Func Desc */ 0x00, /* bmCapabilities: D0+D1 */ 0x01, /* bDataInterface: 1 */ /*ACM Functional Descriptor*/ 0x04, /* bFunctionLength */ 0x24, /* bDescriptorType: CS_INTERFACE */ 0x02, /* bDescriptorSubtype: Abstract Control Management desc */ 0x02, /* bmCapabilities */ /*Union Functional Descriptor*/ 0x05, /* bFunctionLength */ 0x24, /* bDescriptorType: CS_INTERFACE */ 0x06, /* bDescriptorSubtype: Union func desc */ 0x00, /* bMasterInterface: Communication class interface */ 0x01, /* bSlaveInterface0: Data Class Interface */ /*Endpoint 2 Descriptor*/ 0x07, /* bLength: Endpoint Descriptor size */ USB_ENDPOINT_DESCRIPTOR_TYPE, /* bDescriptorType: Endpoint */ CDC_CMD_EP, /* bEndpointAddress */ 0x03, /* bmAttributes: Interrupt */ LOBYTE(CDC_CMD_PACKET_SZE), /* wMaxPacketSize: */ HIBYTE(CDC_CMD_PACKET_SZE), 0xFF, /* bInterval: */ /*---------------------------------------------------------------------------*/ /*Data class interface descriptor*/ 0x09, /* bLength: Endpoint Descriptor size */ USB_INTERFACE_DESCRIPTOR_TYPE, /* bDescriptorType: */ 0x01, /* bInterfaceNumber: Number of Interface */ 0x00, /* bAlternateSetting: Alternate setting */ 0x02, /* bNumEndpoints: Two endpoints used */ 0x0A, /* bInterfaceClass: CDC */ 0x00, /* bInterfaceSubClass: */ 0x00, /* bInterfaceProtocol: */ 0x00, /* iInterface: */ /*Endpoint OUT Descriptor*/ 0x07, /* bLength: Endpoint Descriptor size */ USB_ENDPOINT_DESCRIPTOR_TYPE, /* bDescriptorType: Endpoint */ CDC_OUT_EP, /* bEndpointAddress */ 0x02, /* bmAttributes: Bulk */ LOBYTE(CDC_DATA_MAX_PACKET_SIZE), /* wMaxPacketSize: */ HIBYTE(CDC_DATA_MAX_PACKET_SIZE), 0x00, /* bInterval: ignore for Bulk transfer */ /*Endpoint IN Descriptor*/ 0x07, /* bLength: Endpoint Descriptor size */ USB_ENDPOINT_DESCRIPTOR_TYPE, /* bDescriptorType: Endpoint */ CDC_IN_EP, /* bEndpointAddress */ 0x02, /* bmAttributes: Bulk */ LOBYTE(CDC_DATA_MAX_PACKET_SIZE), /* wMaxPacketSize: */ HIBYTE(CDC_DATA_MAX_PACKET_SIZE), 0x00, /* bInterval: ignore for Bulk transfer */ #ifdef DUAL_COM // IAD 0x08, // bLength: Interface Descriptor size 0x0B, // bDescriptorType: IAD 0x02, // bFirstInterface 0x02, // bInterfaceCount 0x02, // bFunctionClass: CDC 0x02, // bFunctionSubClass 0x01, // bFunctionProtocol 0x02, // iFunction /*Interface Descriptor */ 0x09, /* bLength: Interface Descriptor size */ USB_INTERFACE_DESCRIPTOR_TYPE, /* bDescriptorType: Interface */ /* Interface descriptor type */ 0x02, /* bInterfaceNumber: Number of Interface */ 0x00, /* bAlternateSetting: Alternate setting */ 0x01, /* bNumEndpoints: One endpoints used */ 0x02, /* bInterfaceClass: Communication Interface Class */ 0x02, /* bInterfaceSubClass: Abstract Control Model */ 0x01, /* bInterfaceProtocol: Common AT commands */ 0x00, /* iInterface: */ /*Header Functional Descriptor*/ 0x05, /* bLength: Endpoint Descriptor size */ 0x24, /* bDescriptorType: CS_INTERFACE */ 0x00, /* bDescriptorSubtype: Header Func Desc */ 0x10, /* bcdCDC: spec release number */ 0x01, /*Call Management Functional Descriptor*/ 0x05, /* bFunctionLength */ 0x24, /* bDescriptorType: CS_INTERFACE */ 0x01, /* bDescriptorSubtype: Call Management Func Desc */ 0x00, /* bmCapabilities: D0+D1 */ 0x01, /* bDataInterface: 1 */ /*ACM Functional Descriptor*/ 0x04, /* bFunctionLength */ 0x24, /* bDescriptorType: CS_INTERFACE */ 0x02, /* bDescriptorSubtype: Abstract Control Management desc */ 0x02, /* bmCapabilities */ /*Union Functional Descriptor*/ 0x05, /* bFunctionLength */ 0x24, /* bDescriptorType: CS_INTERFACE */ 0x06, /* bDescriptorSubtype: Union func desc */ 0x00, /* bMasterInterface: Communication class interface */ 0x01, /* bSlaveInterface0: Data Class Interface */ /*Endpoint 2 Descriptor*/ 0x07, /* bLength: Endpoint Descriptor size */ USB_ENDPOINT_DESCRIPTOR_TYPE, /* bDescriptorType: Endpoint */ CDC_CMD_EP, /* bEndpointAddress */ 0x03, /* bmAttributes: Interrupt */ LOBYTE(CDC_CMD_PACKET_SZE), /* wMaxPacketSize: */ HIBYTE(CDC_CMD_PACKET_SZE), 0xFF, /* bInterval: */ /*---------------------------------------------------------------------------*/ /*Data class interface descriptor*/ 0x09, /* bLength: Endpoint Descriptor size */ USB_INTERFACE_DESCRIPTOR_TYPE, /* bDescriptorType: */ 0x03, /* bInterfaceNumber: Number of Interface */ 0x00, /* bAlternateSetting: Alternate setting */ 0x02, /* bNumEndpoints: Two endpoints used */ 0x0A, /* bInterfaceClass: CDC */ 0x00, /* bInterfaceSubClass: */ 0x00, /* bInterfaceProtocol: */ 0x00, /* iInterface: */ /*Endpoint OUT Descriptor*/ 0x07, /* bLength: Endpoint Descriptor size */ USB_ENDPOINT_DESCRIPTOR_TYPE, /* bDescriptorType: Endpoint */ CDC_OUT_EP_EX, /* bEndpointAddress */ 0x02, /* bmAttributes: Bulk */ LOBYTE(CDC_DATA_MAX_PACKET_SIZE), /* wMaxPacketSize: */ HIBYTE(CDC_DATA_MAX_PACKET_SIZE), 0x00, /* bInterval: ignore for Bulk transfer */ /*Endpoint IN Descriptor*/ 0x07, /* bLength: Endpoint Descriptor size */ USB_ENDPOINT_DESCRIPTOR_TYPE, /* bDescriptorType: Endpoint */ CDC_IN_EP_EX, /* bEndpointAddress */ 0x02, /* bmAttributes: Bulk */ LOBYTE(CDC_DATA_MAX_PACKET_SIZE), /* wMaxPacketSize: */ HIBYTE(CDC_DATA_MAX_PACKET_SIZE), 0x00 /* bInterval: ignore for Bulk transfer */ #endif } ;

这两个搞定，其他就是USB处理的细节问题了，包括端点的初始化，端点地址分配，数据发送接收的处理等，具体处理和实现程序可参考附件的工程源码。

成功安装驱动

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设备管理器里面的信息

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单片机程序源码： <ignore_js_op>



Ginkgo_USB_COM.rar


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PC端的驱动安装引导程序： <ignore_js_op>



two_com.rar


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