STM32--USB详细使用说明

硬件原理图

在开始枚举设备的一些初始化

void bsp_USBInit(void)
{

GPIO_InitTypeDef GPIO_InitStructure;

RCC_APB2PeriphClockCmd(RCC_USB_PULL_UP, ENABLE);

USB_CABLE_DISABLE();

GPIO_InitStructure.GPIO_Pin = PIN_USB_PULL_UP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_OD;
GPIO_Init(GPIOB, &GPIO_InitStructure);

{
NVIC_InitTypeDef NVIC_InitStructure;

NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);
NVIC_InitStructure.NVIC_IRQChannel = USB_LP_CAN1_RX0_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
}

RCC_USBCLKConfig(RCC_USBCLKSource_PLLCLK_1Div5);

RCC_APB1PeriphClockCmd(RCC_APB1Periph_USB, ENABLE);

USB_Init();

}

现在开始分析真正的初始化

第一步：初始化，总线复位及向默认地址 0发送 GET_DESCRIPTOR 指令包，请求设备描述

1）Index[4 - 5]：表示 USB插入总线复位；

2）Index[7 - 8]：表示主机向默认地址发送GET_DESCRIPTOR指令包，详细信
息也抓出来了，如（图二）所示

3）Index[15 - 17]：表示设备向主机发送设备描述数据 Index[16]
4）Index[18 - 19]：表示主机完成 GET_DESCRIPTOR指令后，给设备发送一个
空应答

现在具体的分析１０３的ｕｓｂ的执行过程 按顺序向下执行

***************（1）**************

DEVICE_INFO *pInformation;

DEVICE_PROP *pProperty;

DEVICE_PROP Device_Property =
{
Joystick_init,
Joystick_Reset,
Joystick_Status_In,
Joystick_Status_Out,
Joystick_Data_Setup,
Joystick_NoData_Setup,
Joystick_Get_Interface_Setting,
Joystick_GetDeviceDescriptor,
Joystick_GetConfigDescriptor,
Joystick_GetStringDescriptor,
0,
0x40
};

USER_STANDARD_REQUESTS User_Standard_Requests =
{
Joystick_GetConfiguration,
Joystick_SetConfiguration,
Joystick_GetInterface,
Joystick_SetInterface,
Joystick_GetStatus,
Joystick_ClearFeature,
Joystick_SetEndPointFeature,
Joystick_SetDeviceFeature,
Joystick_SetDeviceAddress
};

//USB内核将主机发送过来的用于实现USB设备的设置包保存在设备信息结构表中
typedef struct _DEVICE_INFO
{
uint8_t USBbmRequestType;
uint8_t USBbRequest;
uint16_t_uint8_t USBwValues;
uint16_t_uint8_t USBwIndexs;
uint16_t_uint8_t USBwLengths;

uint8_t ControlState;
uint8_t Current_Feature;
uint8_t Current_Configuration;
uint8_t Current_Interface;
uint8_t Current_AlternateSetting;

ENDPOINT_INFO Ctrl_Info;
}DEVICE_INFO;

usb_init.c文件里面的

void USB_Init(void)
{
pInformation = &Device_Info;
pInformation->ControlState = 2;
pProperty = &Device_Property;
pUser_Standard_Requests = &User_Standard_Requests;

pProperty->Init();
}

***************（2）**************通过函数指针指向这个初始化函数pProperty 在usb_prop.c文件里面

void Joystick_init(void)
{

Get_SerialNum();//得到串行号

pInformation->Current_Configuration = 0;//

PowerOn();//将USB上电 连接设备

USB_SIL_Init();//主要是CNTR寄存器的初始化
bDeviceState = UNCONNECTED;//设备状态标志 当前状态未连接
}

hw_config.c文件里面 这个和标准的不一样有改动，获取设备版本号，将其存入到版本号字符串。

void Get_SerialNum(void) //得到串行号
{
uint32_t Device_Serial0, Device_Serial1, Device_Serial2;
Device_Serial0 = *(__IO uint32_t*)(0x1FFFF7E8);
Device_Serial1 = *(__IO uint32_t*)(0x1FFFF7EC);
Device_Serial2 = *(__IO uint32_t*)(0x1FFFF7F0);
Device_Serial0 += Device_Serial2;
if (Device_Serial0 != 0)
{
IntToUnicode (Device_Serial0, &Joystick_StringSerial[2] , 8);
IntToUnicode (Device_Serial1, &Joystick_StringSerial[18], 4);
}
}

usb_pwr.c文件里面 在这个文件里面只是使能了复位，挂起，唤醒中断，在PowerOn函数使能了复位中断以后，将进入到USB的复位中断里面去。

然后再执行函数USB_SIL_Init 将所有的USB中断都打开。在D+被接通上拉以后，设备就能被主机检测到。

RESULT PowerOn(void)
{
#ifndef STM32F10X_CL
uint16_t wRegVal;

USB_Cable_Config(ENABLE);//将US