BulkLoop例程解读

bulkloop例程是USB固件开发中的基础例程，通过它我们可以学到很多基础知识，我在这里也利用下午的时间来学习一下bulkloop例程。   

bulkloop这个名字就说明了该固件的作用：以bulk型endpoint作为输出和输入端口，让数据"转一圈"。就是在主机端输出一组数据到FX2LP的某一个bulk型endpoint（比如EP2）的缓存中，然后固件将EP2缓存中的数据转移到另一个bulk型endpoint（比如EP6）的缓存中去，当主机端从EP6输入数据的时候，就会发现得到的数据正是之前输出到EP2的数据。   

图1 固件工程Keil界面 :   

bulkloop工程本身用到的源文件有：fw.c、bulkloop.c、dscr.a51、EZUSB.LIB、USBjmpTb.OBJ。

fw.c：固件框架程序FrameWork，它包含了固件程序的主程序。框架程序使FX2LP固件有一个相对固定的运行模式，这使得开发者能够更清楚在什么地方、什么时候应该干什么。

下面是fw.c文件中的代码和我的注释，其中还有不明白的地方:

//-----------------------------------------------------------------------------
//   File:      fw.c
//   Contents:  Firmware frameworks task dispatcher and device request parser
//
// $Archive: /USB/Examples/FX2LP/bulkext/fw.c $
// $Date: 3/23/05 2:53p $
// $Revision: 8 $
//
//
//-----------------------------------------------------------------------------
// Copyright (c) 2011, Cypress Semiconductor Corporation All rights reserved
//-----------------------------------------------------------------------------
#include "..\inc\fx2.h"                    
#include "..\inc\fx2regs.h"               // F：包含了FX2LP寄存器、IO端口的地址信息，方便以后引用这些寄存器和端口。
#include "..\inc\syncdly.h"            // SYNCDELAY macro  F:包含了延时所用到的宏

//-----------------------------------------------------------------------------
// Constants
//-----------------------------------------------------------------------------
#define DELAY_COUNT   0x9248*8L  // Delay for 8 sec at 24Mhz, 4 sec at 48
#define _IFREQ  48000            // IFCLK constant for Synchronization Delay
#define _CFREQ  48000            // CLKOUT constant for Synchronization Delay

//-----------------------------------------------------------------------------
// Random Macros
//-----------------------------------------------------------------------------
#define   min(a,b) (((a)<(b))?(a):(b))
#define   max(a,b) (((a)>(b))?(a):(b))

//-----------------------------------------------------------------------------
// Global Variables
//-----------------------------------------------------------------------------
volatile BOOL   GotSUD;
BOOL      Rwuen;
BOOL      Selfpwr;
volatile BOOL   Sleep;                  // Sleep mode enable flag

WORD   pDeviceDscr;   // Pointer to Device Descriptor; Descriptors may be moved
WORD   pDeviceQualDscr;
WORD   pHighSpeedConfigDscr;
WORD   pFullSpeedConfigDscr;   
WORD   pConfigDscr;
WORD   pOtherConfigDscr;   
WORD   pStringDscr;   

//-----------------------------------------------------------------------------
// Prototypes
//-----------------------------------------------------------------------------
void SetupCommand(void);
void TD_Init(void);
void TD_Poll(void);
BOOL TD_Suspend(void);
BOOL TD_Resume(void);

BOOL DR_GetDescriptor(void);
BOOL DR_SetConfiguration(void);
BOOL DR_GetConfiguration(void);
BOOL DR_SetInterface(void);
BOOL DR_GetInterface(void);
BOOL DR_GetStatus(void);
BOOL DR_ClearFeature(void);
BOOL DR_SetFeature(void);
BOOL DR_VendorCmnd(void);

// this table is used by the epcs macro 
const char code  EPCS_Offset_Lookup_Table[] =
{
   0,    // EP1OUT
   1,    // EP1IN
   2,    // EP2OUT
   2,    // EP2IN
   3,    // EP4OUT
   3,    // EP4IN
   4,    // EP6OUT
   4,    // EP6IN
   5,    // EP8OUT
   5,    // EP8IN
};

// macro for generating the address of an endpoint's control and status register (EPnCS)
#define epcs(EP) (EPCS_Offset_Lookup_Table[(EP & 0x7E) | (EP > 128)] + 0xE6A1)

//-----------------------------------------------------------------------------
// Code
//-----------------------------------------------------------------------------

// Task dispatcher
void main(void)
{
   DWORD   i;
   WORD   offset;
   DWORD   DevDescrLen;
   DWORD   j=0;
   WORD   IntDescrAddr;
   WORD   ExtDescrAddr;

   // Initialize Global States
   Sleep = FALSE;               // Disable sleep mode
   Rwuen = FALSE;               // Disable remote wakeup
   Selfpwr = FALSE;            // Disable self powered
   GotSUD = FALSE;               // Clear "Got setup data" flag

   // Initialize user device
   TD_Init();            //F:该函数定义在bulkloop.c文件中,是执行用户意图的初始化函数,比如定义端点和FIFO属性等.

   // The following section of code is used to relocate the descriptor table. 
   // The frameworks uses SUDPTRH and SUDPTRL to automate the SETUP requests
   // for descriptors.  These registers only work with memory locations
   // in the EZ-USB internal RAM.  Therefore, if the descriptors are located
   // in external RAM, they must be copied to in internal RAM.  
   // The descriptor table is relocated by the frameworks ONLY if it is found 
   // to be located in external memory.
   pDeviceDscr = (WORD)&DeviceDscr;              //F:DeviceDscr结构体的定义在fw.h文件中,赋值发生在dscr.a51中. 楼下几位情况类似
   pDeviceQualDscr = (WORD)&DeviceQualDscr;
   pHighSpeedConfigDscr = (WORD)&HighSpeedConfigDscr;
   pFullSpeedConfigDscr = (WORD)&FullSpeedConfigDscr;
   pStringDscr = (WORD)&StringDscr;

   // Is the descriptor table in external RAM (> 16Kbytes)?  If yes,
   // then relocate.
   // Note that this code only checks if the descriptors START in 
   // external RAM.  It will not work if the descriptor table spans
   // internal and external RAM.
   if ((WORD)&DeviceDscr & 0xC000)        //F:检测描述符地址是否在外置存储器中
   {
      // first, relocate the descriptors
      IntDescrAddr = INTERNAL_DSCR_ADDR;    //F: fx.h文件中, #define INTERNAL_DSCR_ADDR 0x0080   // Relocate Descriptors to 0x80
      ExtDescrAddr = (WORD)&DeviceDscr;
      DevDescrLen = (WORD)&UserDscr - (WORD)&DeviceDscr + 2;    //F:获得描述符的完整长度,为下面的转移做准备.
      for (i = 0; i < DevDescrLen; i++)
         *((BYTE xdata *)IntDescrAddr+i) = *((BYTE xdata *)ExtDescrAddr+i);

      // update all of the descriptor pointers   //F:将描述指针整体指向内部的描述符.
      pDeviceDscr = IntDescrAddr;
      offset = (WORD)&DeviceDscr - INTERNAL_DSCR_ADDR;
      pDeviceQualDscr -= offset;
      pConfigDscr -= offset;
      pOtherConfigDscr -= offset;
      pHighSpeedConfigDscr -= offset;
      pFullSpeedConfigDscr -= offset;
      pStringDscr -= offset;
   }

   EZUSB_IRQ_ENABLE();            // Enable USB interrupt (INT2) //F:定义在fx.h中, 就是EUSB = 1.
   EZUSB_ENABLE_RSMIRQ();            // Wake-up interrupt        //F:定义在fx.h中, (EICON |= 0x20)

   INTSETUP |= (bmAV2EN | bmAV4EN);     // Enable INT 2 & 4 autovectoring  //F:使能INT2和INT4自动指针

   USBIE |= bmSUDAV | bmSUTOK | bmSUSP | bmURES | bmHSGRANT;   // Enable selected interrupts
   EA = 1;                  // Enable 8051 interrupts

#ifndef NO_RENUM
   // Renumerate if necessary.  Do this by checking the renum bit.  If it
   // is already set, there is no need to renumerate.  The renum bit will
   // already be set if this firmware was loaded from an eeprom.
   //F:如果USBCS寄存器的RENUM位是0,USB核响应设备请求,意味着外接存储器中没有现成的固件(0xC2代表有),需要从主机下载固件.当固件被主机下载到USB之后,会将RENUM位置1.
   if(!(USBCS & bmRENUM))
   {
       EZUSB_Discon(TRUE);   // renumerate
   }
#endif

   // unconditionally re-connect.  If we loaded from eeprom we are
   // disconnected and need to connect.  If we just renumerated this
   // is not necessary but doesn't hurt anything
   // F:这句话是无条件重新连接的节奏,为什么从EEPROM载入之后需要重新连接?
   USBCS &=~bmDISCON;
   //F:时钟控制寄存器& (~0000 0111),后三位都是1,使MCU的MOVX指令速度最慢(9周期),以兼容慢速存储器之类的.
   CKCON = (CKCON&(~bmSTRETCH)) | FW_STRETCH_VALUE; // Set stretch 


   // clear the Sleep flag. //F:sleep旗标用来表示USB是否阻断中断请求.见bulkloop.c文件中的赋值语句.
   Sleep = FALSE;

   // Task Dispatcher  //F:任务分配器
   while(TRUE)               // Main Loop //F:不停循环
   {
      // Poll User Device
      TD_Poll();    //F:重复调用函数,大家想干什么,就在bulkloop.c文件中定义它吧.

      // Check for pending SETUP     //F:查看有无等待中的控制命令
      if(GotSUD)                    //F:GotSUD旗标一看就像是SUDAV(setup data available) IRQ中断请求的好朋友. 见bulkloop.c中的SUDAV中断响应函数.
      {
         SetupCommand();          // Implement setup command \\F:后面有定义.
         GotSUD = FALSE;          // Clear SETUP flag
      }

      // check for and handle suspend.
      // NOTE: Idle mode stops the processor clock.  There are only two
      // ways out of idle mode, the WAKEUP pin, and detection of the USB
      // resume state on the USB bus.  The timers will stop and the
      // processor will not wake up on any other interrupts.
      if (Sleep)
      {
         if(TD_Suspend())
         { 
            Sleep = FALSE;     // Clear the "go to sleep" flag.  Do it here to prevent any race condition between wakeup and the next sleep.
            do
            {
               EZUSB_Susp();         // Place processor in idle mode.    //F:没见到定义???
            }
            while(!Rwuen && EZUSB_EXTWAKEUP());
            // above.  Must continue to go back into suspend if the host has disabled remote wakeup
            // *and* the wakeup was caused by the external wakeup pin.

            // 8051 activity will resume here due to USB bus or Wakeup# pin activity.
            EZUSB_Resume();   // If source is the Wakeup# pin, signal the host to Resume.     //F:没见到定义??? 
            TD_Resume();        //F:函数可自定义,用来在唤醒时执行.
         }   
      }

   }
}

BOOL HighSpeedCapable()
{
   // this function determines if the chip is high-speed capable.
   // FX2 and FX2LP are high-speed capable. FX1 is not - it does
   // not have a high-speed transceiver.

   if (GPCR2 & bmFULLSPEEDONLY)
      return FALSE;
   else
      return TRUE;
}   

// Device request parser 
//F:设备请求分析器,这里大部分是一些日常工作,但是Vendor request有较大的DIY空间,
//有时候用户可以利用自定义的Vendor Request做很多事.
void SetupCommand(void)
{
   void   *dscr_ptr;

   switch(SETUPDAT[1])
   {
      case SC_GET_DESCRIPTOR:                  // *** Get Descriptor
         if(DR_GetDescriptor())
            switch(SETUPDAT[3])         
            {
               case GD_DEVICE:            // Device
                  SUDPTRH = MSB(pDeviceDscr);
                  SUDPTRL = LSB(pDeviceDscr);
                  break;
               case GD_DEVICE_QUALIFIER:            // Device Qualifier
                     // only retuen a device qualifier if this is a high speed
                  // capable chip.
                     if (HighSpeedCapable())
                  {
                      SUDPTRH = MSB(pDeviceQualDscr);
                      SUDPTRL = LSB(pDeviceQualDscr);
                  }
                  else
                  {
                      EZUSB_STALL_EP0();
                  }
                  break;
               case GD_CONFIGURATION:         // Configuration
                  SUDPTRH = MSB(pConfigDscr);
                  SUDPTRL = LSB(pConfigDscr);
                  break;
               case GD_OTHER_SPEED_CONFIGURATION:  // Other Speed Configuration
                  SUDPTRH = MSB(pOtherConfigDscr);
                  SUDPTRL = LSB(pOtherConfigDscr);
                  break;
               case GD_STRING:            // String
                  if(dscr_ptr = (void *)EZUSB_GetStringDscr(SETUPDAT[2]))
                  {
                     SUDPTRH = MSB(dscr_ptr);
                     SUDPTRL = LSB(dscr_ptr);
                  }
                  else 
                     EZUSB_STALL_EP0();   // Stall End Point 0
                  break;
               default:            // Invalid request
                  EZUSB_STALL_EP0();      // Stall End Point 0
            }
         break;
      case SC_GET_INTERFACE:                  // *** Get Interface
         DR_GetInterface();
         break;
      case SC_SET_INTERFACE:                  // *** Set Interface
         DR_SetInterface();
         break;
      case SC_SET_CONFIGURATION:               // *** Set Configuration
         DR_SetConfiguration();
         break;
      case SC_GET_CONFIGURATION:               // *** Get Configuration
         DR_GetConfiguration();
         break;
      case SC_GET_STATUS:                  // *** Get Status
         if(DR_GetStatus())
            switch(SETUPDAT[0])
            {
               case GS_DEVICE:            // Device
                  EP0BUF[0] = ((BYTE)Rwuen << 1) | (BYTE)Selfpwr;
                  EP0BUF[1] = 0;
                  EP0BCH = 0;
                  EP0BCL = 2;
                  break;
               case GS_INTERFACE:         // Interface
                  EP0BUF[0] = 0;
                  EP0BUF[1] = 0;
                  EP0BCH = 0;
                  EP0BCL = 2;
                  break;
               case GS_ENDPOINT:         // End Point
                  EP0BUF[0] = *(BYTE xdata *) epcs(SETUPDAT[4]) & bmEPSTALL;
                  EP0BUF[1] = 0;
                  EP0BCH = 0;
                  EP0BCL = 2;
                  break;
               default:            // Invalid Command
                  EZUSB_STALL_EP0();      // Stall End Point 0
            }
         break;
      case SC_CLEAR_FEATURE:                  // *** Clear Feature
         if(DR_ClearFeature())
            switch(SETUPDAT[0])
            {
               case FT_DEVICE:            // Device
                  if(SETUPDAT[2] == 1)
                     Rwuen = FALSE;       // Disable Remote Wakeup
                  else
                     EZUSB_STALL_EP0();   // Stall End Point 0
                  break;
               case FT_ENDPOINT:         // End Point
                  if(SETUPDAT[2] == 0)
                  {
                     *(BYTE xdata *) epcs(SETUPDAT[4]) &= ~bmEPSTALL;
                     EZUSB_RESET_DATA_TOGGLE( SETUPDAT[4] );
                  }
                  else
                     EZUSB_STALL_EP0();   // Stall End Point 0
                  break;
            }
         break;
      case SC_SET_FEATURE:                  // *** Set Feature
         if(DR_SetFeature())
            switch(SETUPDAT[0])
            {
               case FT_DEVICE:            // Device
                  if(SETUPDAT[2] == 1)
                     Rwuen = TRUE;      // Enable Remote Wakeup
                  else if(SETUPDAT[2] == 2)
                     // Set Feature Test Mode.  The core handles this request.  However, it is
                     // necessary for the firmware to complete the handshake phase of the
                     // control transfer before the chip will enter test mode.  It is also
                     // necessary for FX2 to be physically disconnected (D+ and D-)
                     // from the host before it will enter test mode.
                     break;
                  else
                     EZUSB_STALL_EP0();   // Stall End Point 0
                  break;
               case FT_ENDPOINT:         // End Point
                  *(BYTE xdata *) epcs(SETUPDAT[4]) |= bmEPSTALL;
                  break;
               default:
                  EZUSB_STALL_EP0();      // Stall End Point 0
            }
         break;
      default:                     // *** Invalid Command
         if(DR_VendorCmnd())
            EZUSB_STALL_EP0();            // Stall End Point 0
   }

   // Acknowledge handshake phase of device request
   EP0CS |= bmHSNAK;        //F:进入握手阶段
}

// Wake-up interrupt handler
void resume_isr(void) interrupt WKUP_VECT
{
   EZUSB_CLEAR_RSMIRQ();
}

下面是bulkloop.c文件中的代码和我的注释，其中还有不明白的地方，比如“interrupt 0”:

//-----------------------------------------------------------------------------
//   File:      bulkloop.c
//   Contents:  Hooks required to implement USB peripheral function.
//
// $Archive: /USB/Examples/FX2LP/bulkloop/bulkloop.c $
//
//
//-----------------------------------------------------------------------------
// Copyright (c) 2011, Cypress Semiconductor Corporation All rights reserved
//-----------------------------------------------------------------------------
#pragma NOIV               // Do not generate interrupt vectors //F:告诉编译器,不要使用默认的中断向量表

#include "..\inc\fx2.h"
#include "..\inc\fx2regs.h"
#include "..\inc\syncdly.h"            // SYNCDELAY macro

extern BOOL GotSUD;             // Received setup data flag
extern BOOL Sleep;
extern BOOL Rwuen;
extern BOOL Selfpwr;

BYTE Configuration;             // Current configuration
BYTE AlternateSetting;          // Alternate settings

#define VR_NAKALL_ON    0xD0    //F: 1101 0000
#define VR_NAKALL_OFF   0xD1    //F: 1101 0001

//-----------------------------------------------------------------------------
// Task Dispatcher hooks        //F:任务分配挂钩
//   The following hooks are called by the task dispatcher. //F:挂钩函数是被任务分配器调用的
//-----------------------------------------------------------------------------

void TD_Init(void)             // Called once at startup
{
   // set the CPU clock to 48MHz
   CPUCS = ((CPUCS & ~bmCLKSPD) | bmCLKSPD1) ;    //F:CLKSPD1=1且CLKSPD0=0 意思是48MHz

   // set the slave FIFO interface to 48MHz    
   //F:时钟来源定为外部,内部FIFO\GPIF时钟设为48MHz,IFCLK输出端口为三态,IFCLK极性不翻转,同步方式,PE012为端口,ABD端口为端口模式
   IFCONFIG |= 0x40;

  //F: 下面的寄存器的修改之间需要添加同步延时
  // Registers which require a synchronization delay, see section 15.14
  // FIFORESET        FIFOPINPOLAR
  // INPKTEND         OUTPKTEND
  // EPxBCH:L         REVCTL
  // GPIFTCB3         GPIFTCB2
  // GPIFTCB1         GPIFTCB0
  // EPxFIFOPFH:L     EPxAUTOINLENH:L
  // EPxFIFOCFG       EPxGPIFFLGSEL
  // PINFLAGSxx       EPxFIFOIRQ
  // EPxFIFOIE        GPIFIRQ
  // GPIFIE           GPIFADRH:L
  // UDMACRCH:L       EPxGPIFTRIG
  // GPIFTRIG
  
  // Note: The pre-REVE EPxGPIFTCH/L register are affected, as well...
  //      ...these have been replaced by GPIFTC[B3:B0] registers

  // default: all endpoints have their VALID bit set
  // default: TYPE1 = 1 and TYPE0 = 0 --> BULK  
  // default: EP2 and EP4 DIR bits are 0 (OUT direction)
  // default: EP6 and EP8 DIR bits are 1 (IN direction)
  // default: EP2, EP4, EP6, and EP8 are double buffered

  // we are just using the default values, yes this is not necessary...
  EP1OUTCFG = 0xA0;
  EP1INCFG = 0xA0;
  SYNCDELAY;                    // see TRM section 15.14
  EP2CFG = 0xA2; //F:1010 0010意思是:有效,OUT,Bulk,512,0,Double.
  SYNCDELAY;                    
  EP4CFG = 0xA0; //F:1010 0000意思是:有效,OUT,Bulk,512,0,00(4和8端点的末尾两位只能是0,在2和6都是Double情况下,意味着Double).
  SYNCDELAY;                    
  EP6CFG = 0xE2; //F:1110 0010意思是:有效,IN,Bulk,512,0,Double.
  SYNCDELAY;                    
  EP8CFG = 0xE0; //F:1110 0000意思是:有效,OUT,Bulk,512,0,00.

  // out endpoints do not come up armed //F:输出端点一开始没有被arm.
  
  // since the defaults are double buffered we must write dummy byte counts twice
  //F:因为端点默认是双倍缓冲(512*2),我们必须用无用数据写两次字节计数,用来arm输出端点.
  SYNCDELAY;                    
  EP2BCL = 0x80;                // arm EP2OUT by writing byte count w/skip.
  SYNCDELAY;                    
  EP2BCL = 0x80;
  SYNCDELAY;                    
  EP4BCL = 0x80;                // arm EP4OUT by writing byte count w/skip.
  SYNCDELAY;                    
  EP4BCL = 0x80;    

  // enable dual autopointer feature //F:使能自动指针
  AUTOPTRSETUP |= 0x01;

}


void TD_Poll(void)              // Called repeatedly while the device is idle //F:重复调用
{
  WORD i;
  WORD count;

  if(!(EP2468STAT & bmEP2EMPTY))    //F:如果EP2的buff不空.EP2468STAT中的各个位其实就是EPxCS中的F和E位,标识满\空.
  { // check EP2 EMPTY(busy) bit in EP2468STAT (SFR), core set's this bit when FIFO is empty
     if(!(EP2468STAT & bmEP6FULL))    //F:如果EP6的buff不满.
     {  // check EP6 FULL(busy) bit in EP2468STAT (SFR), core set's this bit when FIFO is full
        APTR1H = MSB( &EP2FIFOBUF );    //F:自动指针1指向EP2的buffer
        APTR1L = LSB( &EP2FIFOBUF );

        AUTOPTRH2 = MSB( &EP6FIFOBUF );    //F:自动指针2指向EP6的buffer
        AUTOPTRL2 = LSB( &EP6FIFOBUF );

        count = (EP2BCH << 8) + EP2BCL;    //F:计算EP2有多少字节

        // loop EP2OUT buffer data to EP6IN
        for( i = 0x0000; i < count; i++ )
        {
           // setup to transfer EP2OUT buffer to EP6IN buffer using AUTOPOINTER(s)
           // F:利用自动指针进行EP2和EP6之间的数据转移
           EXTAUTODAT2 = EXTAUTODAT1; // F:自动指针1指向的数据到自动指针2指向的空间
        }
        EP6BCH = EP2BCH;      //F:宝贝数据长度到EP6的计数,准备接下来的IN操作
        SYNCDELAY;  
        EP6BCL = EP2BCL;        // arm EP6IN
        SYNCDELAY;                    
        EP2BCL = 0x80;          // re(arm) EP2OUT
     }
  }

  if(!(EP2468STAT & bmEP4EMPTY))
  { // check EP4 EMPTY(busy) bit in EP2468STAT (SFR), core set's this bit when FIFO is empty
     if(!(EP2468STAT & bmEP8FULL))
     {  // check EP8 FULL(busy) bit in EP2468STAT (SFR), core set's this bit when FIFO is full
        APTR1H = MSB( &EP4FIFOBUF );
        APTR1L = LSB( &EP4FIFOBUF );

        AUTOPTRH2 = MSB( &EP8FIFOBUF );
        AUTOPTRL2 = LSB( &EP8FIFOBUF );

        count = (EP4BCH << 8) + EP4BCL;

        // loop EP4OUT buffer data to EP8IN
        for( i = 0x0000; i < count; i++ )
        {
           // setup to transfer EP4OUT buffer to EP8IN buffer using AUTOPOINTER(s)
           EXTAUTODAT2 = EXTAUTODAT1;
        }
        EP8BCH = EP4BCH;  
        SYNCDELAY;  
        EP8BCL = EP4BCL;        // arm EP8IN
        SYNCDELAY;                    
        EP4BCL = 0x80;          // re(arm) EP4OUT
     }
  }
}

BOOL TD_Suspend(void)          // Called before the device goes into suspend mode 可自定义
{
   return(TRUE);
}

BOOL TD_Resume(void)          // Called after the device resumes 可自定义
{
   return(TRUE);
}

//-----------------------------------------------------------------------------
// Device Request hooks 设备请求执行函数,大多数可自定义
//   The following hooks are called by the end point 0 device request parser.
//-----------------------------------------------------------------------------

BOOL DR_GetDescriptor(void)
{
   return(TRUE);
}

BOOL DR_SetConfiguration(void)   // Called when a Set Configuration command is received
{
   Configuration = SETUPDAT[2];    //F:Configuration这个变量是哪里定义的?还是编译器内部定义的?如何与描述符表联系在一起???
   return(TRUE);            // Handled by user code
}

BOOL DR_GetConfiguration(void)   // Called when a Get Configuration command is received
{
   EP0BUF[0] = Configuration;
   EP0BCH = 0;
   EP0BCL = 1;                //F: arm EP0
   return(TRUE);            // Handled by user code
}

BOOL DR_SetInterface(void)       // Called when a Set Interface command is received
{
   AlternateSetting = SETUPDAT[2];
   return(TRUE);            // Handled by user code
}

BOOL DR_GetInterface(void)       // Called when a Set Interface command is received
{
   EP0BUF[0] = AlternateSetting;
   EP0BCH = 0;
   EP0BCL = 1;
   return(TRUE);            // Handled by user code
}

BOOL DR_GetStatus(void)
{
   return(TRUE);
}

BOOL DR_ClearFeature(void)
{
   return(TRUE);
}

BOOL DR_SetFeature(void)
{
   return(TRUE);
}

BOOL DR_VendorCmnd(void)    //F:生产商请求
{
  BYTE tmp;
  
  switch (SETUPDAT[1])
  {
     case VR_NAKALL_ON:        //F:NAK所有transfer请求
        tmp =FIFORESET;        //F:为什么不直接 FIFORESET|=bmNAKALL ???
        tmp |= bmNAKALL;      
        SYNCDELAY;                    
        FIFORESET = tmp;    //F:这样费周折是因为FIFORESET不可以按位访问吗???
        break;
     case VR_NAKALL_OFF:    
        tmp = FIFORESET;
        tmp &= ~bmNAKALL;      
        SYNCDELAY;                    
        FIFORESET = tmp;
        break;
     default:
        return(TRUE);
  }

  return(FALSE);
}

//-----------------------------------------------------------------------------
// USB Interrupt Handlers
//   The following functions are called by the USB interrupt jump table.
//-----------------------------------------------------------------------------

// Setup Data Available Interrupt Handler
void ISR_Sudav(void) interrupt 0    //F:有控制传输的8字节数据到达
{
   GotSUD = TRUE;            // Set flag
   EZUSB_IRQ_CLEAR();        //F:重置中断请求,write 0 to EXIF.5
   USBIRQ = bmSUDAV;         // Clear SUDAV IRQ //F:向指定的位写1以清楚终端请求
}

// Setup Token Interrupt Handler
void ISR_Sutok(void) interrupt 0    //F:USB内核接收到Setup传输的Token 
{
   EZUSB_IRQ_CLEAR();
   USBIRQ = bmSUTOK;         // Clear SUTOK IRQ
}

void ISR_Sof(void) interrupt 0        //F:USB内核收到 Start of Frame packet
{
   EZUSB_IRQ_CLEAR();
   USBIRQ = bmSOF;            // Clear SOF IRQ
}

void ISR_Ures(void) interrupt 0    //F:USB Reset Interrupt Request
{
   // whenever we get a USB reset, we should revert to full speed mode
   //任何时刻接收到USB reset,都应该滚回全速模式
   pConfigDscr = pFullSpeedConfigDscr;
   ((CONFIGDSCR xdata *) pConfigDscr)->type = CONFIG_DSCR;
   pOtherConfigDscr = pHighSpeedConfigDscr;
   ((CONFIGDSCR xdata *) pOtherConfigDscr)->type = OTHERSPEED_DSCR;

   EZUSB_IRQ_CLEAR();
   USBIRQ = bmURES;         // Clear URES IRQ
}

void ISR_Susp(void) interrupt 0
{
   Sleep = TRUE;
   EZUSB_IRQ_CLEAR();
   USBIRQ = bmSUSP;
}

void ISR_Highspeed(void) interrupt 0
{
   if (EZUSB_HIGHSPEED())
   {
      pConfigDscr = pHighSpeedConfigDscr;
      ((CONFIGDSCR xdata *) pConfigDscr)->type = CONFIG_DSCR;
      pOtherConfigDscr = pFullSpeedConfigDscr;
      ((CONFIGDSCR xdata *) pOtherConfigDscr)->type = OTHERSPEED_DSCR;
   }

   EZUSB_IRQ_CLEAR();
   USBIRQ = bmHSGRANT;
}
void ISR_Ep0ack(void) interrupt 0
{
}
void ISR_Stub(void) interrupt 0
{
}
void ISR_Ep0in(void) interrupt 0
{
}
void ISR_Ep0out(void) interrupt 0
{
}
void ISR_Ep1in(void) interrupt 0
{
}
void ISR_Ep1out(void) interrupt 0
{
}
void ISR_Ep2inout(void) interrupt 0
{
}
void ISR_Ep4inout(void) interrupt 0
{
}
void ISR_Ep6inout(void) interrupt 0
{
}
void ISR_Ep8inout(void) interrupt 0
{
}
void ISR_Ibn(void) interrupt 0
{
}
void ISR_Ep0pingnak(void) interrupt 0
{
}
void ISR_Ep1pingnak(void) interrupt 0
{
}
void ISR_Ep2pingnak(void) interrupt 0
{
}
void ISR_Ep4pingnak(void) interrupt 0
{
}
void ISR_Ep6pingnak(void) interrupt 0
{
}
void ISR_Ep8pingnak(void) interrupt 0
{
}
void ISR_Errorlimit(void) interrupt 0
{
}
void ISR_Ep2piderror(void) interrupt 0
{
}
void ISR_Ep4piderror(void) interrupt 0
{
}
void ISR_Ep6piderror(void) interrupt 0
{
}
void ISR_Ep8piderror(void) interrupt 0
{
}
void ISR_Ep2pflag(void) interrupt 0
{
}
void ISR_Ep4pflag(void) interrupt 0
{
}
void ISR_Ep6pflag(void) interrupt 0
{
}
void ISR_Ep8pflag(void) interrupt 0
{
}
void ISR_Ep2eflag(void) interrupt 0
{
}
void ISR_Ep4eflag(void) interrupt 0
{
}
void ISR_Ep6eflag(void) interrupt 0
{
}
void ISR_Ep8eflag(void) interrupt 0
{
}
void ISR_Ep2fflag(void) interrupt 0
{
}
void ISR_Ep4fflag(void) interrupt 0
{
}
void ISR_Ep6fflag(void) interrupt 0
{
}
void ISR_Ep8fflag(void) interrupt 0
{
}
void ISR_GpifComplete(void) interrupt 0
{
}
void ISR_GpifWaveform(void) interrupt 0
{
}