usbgetdescriptor.c

在51下的外挂硬盘和FLASH的MP3方案程序以及原理图

#ifndef _USB_DEFINE
 #include "USB.c"
#endif

void USBGetDescriptor(void)
{
	switch (USBSetup->wValue&0x00ff)
	{
		case USB_GET_DESC_DEVICE		:
			USBEP0Buffer.Out=USBDeviceDescriptor;
			USBEP0Buffer.OutLength=USBDeviceDescriptor[0];				//设备描述表长度
			break;
		case USB_GET_DESC_CONFIGURATION	:
				USBEP0Buffer.Out=USBConfigurationDescriptor;
			if (USBSetup->wLength>0x1800)							//配置描述标的长度
				USBEP0Buffer.OutLength=sizeof(USBConfigurationDescriptor) 
					+ sizeof(USBInterfaceDescriptor)
					+ sizeof(USBEndpoint1Descriptor)
					+ sizeof(USBEndpoint2Descriptor);
			else
				USBEP0Buffer.OutLength=USBConfigurationDescriptor[0];
			break;
		case USB_GET_DESC_STRING		:
			switch (USBEP0Buffer.In[2])
			{
				case 0x00		:
					USBEP0Buffer.Out=USBString1Descriptor;
					USBEP0Buffer.OutLength=sizeof(USBString1Descriptor);
					break;
				case 0x01		:
					USBEP0Buffer.Out=USBString3Descriptor;
					USBEP0Buffer.OutLength=sizeof(USBString3Descriptor);
					break;
				case 0x02		:
					USBEP0Buffer.Out=USBString3Descriptor;
					USBEP0Buffer.OutLength=sizeof(USBString3Descriptor);
					break;
				case 0x03		:
					USBEP0Buffer.Out=USBString3Descriptor;
					USBEP0Buffer.OutLength=sizeof(USBString3Descriptor);
					break;
			}
			break;
		case USB_GET_DESC_INTERFACE		:
			USBEP0Buffer.Out=USBInterfaceDescriptor;
			USBEP0Buffer.OutLength=sizeof(USBInterfaceDescriptor);
			break;
		case USB_GET_DESC_ENDPOINT		:
			USBEP0Buffer.Out=USBEndpoint1Descriptor;
			USBEP0Buffer.OutLength=sizeof(USBEndpoint1Descriptor);
			break;
		default							:
			break;
	}
	USBEP0WritePacket();
	if (USBEP0Buffer.OutLength==0x20&&USBSetup->wLength>0x2000)				//发送0字节包
	{
		SET_BIT_7(UEPSTAX);						//设置DIR
		SET_BIT_4(UEPSTAX);						//设置TXRDY
		while(!( UEPSTAX & 0x01 ));				//等待TXCMP
		CLEAR_BIT_0(UEPSTAX);					//清除TXCMP
	}

}