【工学】USB通信协议 共(16页)

做了一段时间的USB方面的开发，虽然是现成的方案，我们只需要搞清楚它的架构,再添加我们的代码就行了。

空闲之余，研究了一下USB通信过程，也把82A851R部分的汇编代码重新用C语言描述了一篇（仅是描述，不代表能真正运行）。

发现汇编代码条理性太在太差了，不好读。

一把C语言的代码一写，马上觉得清楚很多。

废话少说，开始贴图，贴代码。

＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝下面是将一些函数重新用C语言描述了一遍＝＝＝＝＝＝＝＝＝＝＝＝#define BYTE unsigned char//**************************************************// 基本定义函数//**************************************************BYTE FIFO_RD_CHECK(BYTE num){BYTE FIFO_FLAG=0;UCC|=num;//选择Endpoint,0,1,2,3,4,MISC&=0xf8;//低3位置0MISC|=0X00;//TX位置0;Delay_3us();MISC|=0X01;//Set RequestDelay_28us();if(MISC&0X40!=0) FIFO_FLAG=0x0f;//READYif(MISC&0x80!=0) FIF0_FLAG&=0xf0;//Len0 DetectedMISC&=0xfe;//clear REQreturn FIFO_FLAG;}BYTE FIFO_WR_CHECK(BYTE num){BYTE FIFO_FLAG=0;//后4位表示Ready位,前四位表示Len0位的状态是否有被设置UCC|=num;//选择Endpoint,0,1,2,3,4,MISC&=0xf8;//低3位置0MISC|=0X02;//TX位置0;Delay_3us();MISC|=0X01;//Set RequestDelay_28us();if(MISC&0X40!=0) FIFO_FLAG=0x0f;//READYif(MISC&0x80!=0) FIF0_FLAG&=0xf0;//Len0 DetectedMISC&=0xfe;//clear REQreturn FIFO_FLAG;}void Read_FIFO(BYTE *Fifo_Addr,BYTE Fifo_Size,BYTE *buffer){int i=0;MISC|=0x01;//Set Requestfor(i=0;i<Fifo_Size;i++){buffer[i]=Fifo_Addr[0];//从FIFO地址取值Delay_28us();if(MISC&0x40==0) break;//Not Ready}MISC^=0X02;//改变TX位状态Delay_3us();MISC&=0XFE;//Clear Request}void Write_FIFO(BYTE *Fifo_Addr,BYTE SendLenth,BYTE *buffer){int i=0;MISC|=0X01;//Set Requestfor(i=0;i<SendLenth;i++){Fifo_Addr[0]=buffer[i];//将要发送的数据放至相应的Fifo中Delay_28us();if(MISC&0x40==0) break;//Not Ready}MISC^=0X02;//改变TX位状态Delay_3us();MISC&=0XFE;//Clear Request}BOOL Check_Real_Cmd(){BYTE bFlag_Real_Cmd=FALSE;if(MISC&0X20!=0) bFlag_Real_Cmd=TRUE;if(MISC&0X80!=0) bFlag_Real_Cmd=TRUE;return bFlag_Real_Cmd;}void Send_hand(){BOOL IsRealCmd,Status_Flag;while(1){IsRealCmd=Check_Real_Cmd();if(IsRealCmd==TRUE)return;else{Status_Flag=FIFO_WR_CHECK(0);if(Status_Flag&0x0f!=0)//Fifo_Readybreak;elsecontinue;}}MISC|=0x01;//Set RequsetMISC^=0X02;//改变TX位状态Delay_3us();MISC&=0XFE;//Clear Request}void control_read(WORD *rom_dataptr,BYTE *buffer)//从中读取数据, { //rom_dataptr是全局的在其他函数中赋值改变BYTE temp,i=0;if(buffer[7]!=0) //FIFO_WLENGTHHreturn;if(buffer[6]==0) //FIFO_WLENGTHLreturn;if(buffer[6]>data_start[0])//请求的数据超出ROM数据return;data_count=buffer[6];if(MISC&0x40!=0)//是控制指令return;if(data_count==0){Send_Hand_Shake();return;}//开始真正的control_readwhile(1){if(bFlag_RD_HT able==0)//Read Low Byte{bFlag_RD_HT able=1;buffer[i]=(BYTE )*rom_dataptr;//取其低位i++;data_count--;//全局变量,要发送的总长度if(data_count<=1)break;if(i+1==8)//FIFO_size=8break;}else//Read Hight Byte{bFlag_RD_HT able=0;buffer[i]=(BYTE )(*rom_dataptr)>>8;//取其高位rom_dataptr++;//将ROM指针前移if(buffer[i]==0x3f)continue;else{i++;if(data_count<=1)break;if(i+1==8)break;}}}//填充完毕,结束循环,开始向FIFO发送数据while(1)if(Check_Real_Cmd()==TRUE) return;if(FIFO_WR_CHECK(0)&0xff==0) continue;//Not Ready}Write_FIFO(Fifo_0_Addr,0x02,buffer);}//**************************************************// SetAddress(): 重新设定Endpoint地址函数//**************************************************void SetAddress(BYTE *buffer){BYTE Dev_Addr;Dev_Addr=buffer[2]//FIFO_OUT3,FIFO_WVALUELSIES|=0x01;//主机从设备读操作后将更新在AWR中的地址,否则为0则立即更新Dev_Addr&=0XFE;USB_AWR=Dev_Addr;Send_Hand_Shake();}//**************************************************// SetConfiguration(): 设置配置函数//**************************************************void SetConfiguration(BYTE *buffer,BYTE *USB_Configuration){USVC|=0x80;PGA_CTRL|=0x80;*USB_Configuration=buffer[2];//FIFO_WVALUELSTALL&=0x00;//设置好以上的寄存器Send_Hand_Shake();}//**************************************************// ClearFeature(): 清徐Feature函数//**************************************************void ClearFeature(BYTE *buffer){BYTE temp;temp=buffer[2];//FIFO_wValueLif(temp=0x01){Send_Hand_Shake();elseSTALL0|=0x01;//SendStall0();}void ClearFeature_Endpoint(BYTE *buffer){BYTE temp;temp=buffer[4];//FIFO_wIndexLif(bFlag_SetConfiguration_Ready==TRUE);//表明已经配置过了temp=GetPipeBit(temp);//获取对应位temp=~temp;//取反STALL=temp&STALL;//与STALL寄存器相与,将需要的位置0Send_Hand_Shake();}//************************************************** // SetFeature(): 设置Feature函数// 包括Endpoint部分//************************************************** void SetFeature(BYTE *buffer){BYTE FIFO_wValueL=buffer[2];BYTE FIFO_wValueH=buffer[3];if(FIFO_wValueH==0x00){if(FIFO_wValueL==0x01){Send_Hand_Shake();}elseSTALL0|=0x01;//SendStall0();}else if(FIFO_wValueH>=0X81<=0X84){if(FIFO_wValueL==0x00){Send_Hand_Shake();}elseSTALL0|=0x01;//SendStall0();}else STALL0|=0x01;//SendStall0();}void SetFeature_Endpoint(BYTE *buffer){BYTE temp;temp=buffer[4];//FIFO_wIndexLif(bFlag_SetConfiguration_Ready!=TRUE)return;//有没有被SetConfiguration()设置temp&=0x7f;temp=GetPipeBit(temp);//获取对应位STALL=temp|STALL;//将指定的Enpoint置1Send_Hand_Shake();}//**************************************************// SetInterface(): 设置Interface函数////**************************************************BOOL SetInterface(BYTE *buffer,BYTE *USB_Interface_Alt,BYTE *USB_Interface) {*USB_Interface_Alt=buffer[2];//FIFO_WVALUEL*USB_Interface=buffer[4];//FIFO_WINDEXLPA|=0X01;//Set PA.0Send_Hand_Shake();return TRUE;}//**************************************************// GetDescriptor(): 获取Descriptor// 描述的函数//**************************************************void GetDescriptor(BYTE *buffer){BYTE FIFO_WvalueH=buffer[3];BYTE FIFO_wIndexL=buffer[4];switch(FIFO_WvalueH){case 01://device, 80 06 00 01GetDeviceDescriptor();return;case 02://configurationDescriptor 80 06 00 02GetConfigurationDescriptor();return;case 03://string,80 06 00 03GetStringDescriptor();default:break;}//**********************************//****Then test for HID class Descriptor//***********************************if(FIFO_wIndexL==0x03)//Check Interface 3,被配置为HID{switch(FIFO_WvalueH){case 22://report,81 06 00 22GetReportDescriptor();break;case 21://HID,81 06 00 21GetHIDDescriptor();break;default:STALL0|=0x01;//SendStall0();//无法解析的情况break;}}elseSTALL0|=0x01;//SendStall0();//无法解析的情况}void GetDeviceDescriptor(BYTE *buffer){BYTE data_count;BYTE *data_start;data_count=device_desc_table[0];//低字节存放长度data_start=device_desc_table;}//************************************************** // GetStatus(): 设置USB状态的函数// 包括Endpoint部分//************************************************** void GetStatus(BYTE *buffer){BYTE FIFO_SendLen=0X02;buffer[0]=0x00;buffer[1]=0x01;while(1){if(Check_Real_Cmd()==TRUE) break;//估计是Len0=1,结束会话if(FIFO_WR_CHECK(0)==FALSE) continue;}Write_FIFO(Fifo_0_Addr,FIFO_SendLen,buffer);}GetStatus_Endpoint(BYTE *buffer){BYTE FIFO_SendLen=0X02;BYTE temp;temp=buffer[4];//FIFO_wIndexL,表示要检测的Endpoint号temp&=0x7f;temp=GetPipeBit(temp);//获取位数如:0000 00101B => 0010 0000B if(temp&STALL==TRUE)//要检测的位置1buffer[0]=1;else buffer[0]=0;buffer[1]=0;while(1){if(Check_Real_Cmd()==TRUE) break;//估计是Len0=1,结束会话if(FIFO_WR_CHECK(0)==FALSE) continue;}Write_FIFO(Fifo_0_Addr,FIFO_SendLen,buffer);}//**************************************************// GetConfiguration(): 设置配置的函数////**************************************************void GetConfiguration(BYTE *buffer,BYTE USB_Configuration){BYTE FIFO_SendLen;buffer[0]=USB_Configuration;FIFO_SendLen=0x01;while(1){if(Check_Real_Cmd()==TRUE) return;if(FIFO_WR_CHECK(0)&0x0f!=0)//Fifo Readybreak;}Write_FIFO(Fifo_0_Addr,FIFO_SendLen,buffer);}//************************************************** // GetInterface(): 获取Interface接口的函数////************************************************** void GetInterface(BYTE USB_Interface_Alt,BYTE *buffer){BYTE FIFO_SendLen;buffer[0]=USB_Interface_Alt;FIFO_SendLen=0x01;while(1){if(Check_Real_Cmd()==TRUE) return;if(FIFO_WR_CHECK(0)&0xff==0) continue;//Not Ready }Write_FIFO(Fifo_0_Addr,FIFO_SendLen,buffer)}//************************************************** // SetReport(): 设置Report的函数////************************************************** BYTE SetReport(BYTE *buffer){BYTE FIFO_wValueH=buffer[3];BYTE nCmdIndex1;if(FIFO_wValueH==0x02)//set_output_report{if(buffer[4]!=0x03)//check interface{STALL|=0x01;//ENPOINT0 Errorreturn;}if(buffer[6]!=0x08)//FIFO_wLengthL,check length{STALL|=0x01;//ENPOINT0 Errorreturn;}nCmdIndex1=0x21;}return nCmdIndex1;//返回命令索引号}//**************************************************// SetCur(): 设置当前信息的函数// 包括VolumeControl,MuteControl//**************************************************void SetCur(BYTE *buffer)//;21 01{if(buffer[3]==0x01)//MUTE_CONTROLMuteControl();else if(buffer[3]==0x02)//VOLUME_CONTROLVolumeControl();elseSTALL0|=0x01;}BYTE MuteControl(BYTE *buffer) //21 01 00 01,if have more feature , the state must be modify!!{BYTE nCmdIndex1;if(buffer[5]==0x02)//FIFO_wIndexH,MuteControl_SetSpeaker();{nCmdIndex1=0x18;return nCmdIndex1;}else if(buffer[5]==0x06)//MuteControl_SetMic();{nCmdIndex1=0x19;return nCmdIndex1;}}BYTE VolumeControl(BYTE *buffer){BYTE nCmdIndex1;if(buffer[5]==0x02)//FIFO_wIndexH,VolumeControl_SetSpeaker(){nCmdIndex1=0x28;return nCmdIndex1;}else ifbuffer[5]==0x06){nCmdIndex1=0x29;return nCmdIndex1;}}//************************************************** // GetMin(): 获取各种最小信息的函数// 包括GetMin_SetSpeaker,GetMin_SetMic//************************************************** void GetMin(BYTE *buffer){if(buffer[5]==0x02)//FIFO_wIndexHGetMin_SetSpeaker();else if(buffer[5]==0x06)GetMin_SetMic();elseSTALL|=0X01;}void GetMin_SetSpeaker(BYTE *buffer){buffer[0]=0x00;buffer[1]=0xe0;//Min_Volumewhile(1){if(Check_Real_Cmd()==TRUE) return;if(FIFO_WR_CHECK(0)&0xff==0) continue;//Not Ready }Write_FIFO(Fifo_0_Addr,0x02,buffer)}void GetMin_SetMic(BYTE *buffer){buffer[0]=0x00;buffer[1]=0x00;//MIC_Min_Volumewhile(1){if(Check_Real_Cmd()==TRUE) return;if(FIFO_WR_CHECK(0)&0xff==0) continue;//Not Ready }Write_FIFO(Fifo_0_Addr,0x02,buffer)}//************************************************** // GetMax(): 获取各种最大信息的函数// 包括Speaker,Mic//************************************************** void GetMax(BYTE *buffer)if(buffer[5]==0x02)//FIFO_wIndexHGetMax_SetSpeaker();else if(buffer[5]==0x06)GetMax_SetMic();elseSTALL0|=0x01;}void GetMax_SetSpeaker(BYTE *buffer){buffer[0]=0x00;buffer[1]=0x0c;//Max_Volumewhile(1){if(Check_Real_Cmd()==TRUE) return;if(FIFO_WR_CHECK(0)&0xff==0) continue;//Not Ready }Write_FIFO(Fifo_0_Addr,0x02,buffer)}void GetMax_SetMic(BYTE *buffer){buffer[0]=0x00;buffer[1]=0x0c;//MIC_Max_Volumewhile(1){if(Check_Real_Cmd()==TRUE) return;if(FIFO_WR_CHECK(0)&0xff==0) continue;//Not Ready }Write_FIFO(Fifo_0_Addr,0x02,buffer)}//************************************************** // GetRes():////************************************************** void GetRes(BYTE *buffer){buffer[0]=0x00;buffer[1]=0x01;while(1){if(Check_Real_Cmd()==TRUE) return;if(FIFO_WR_CHECK(0)&0xff==0) continue;//Not Ready }Write_FIFO(Fifo_0_Addr,0x02,buffer)}//************************************************** // GetCur():////************************************************** void GetCur(BYTE *buffer){BYTE FIFO_wLengthL=buffer[6];BYTE FIFO_wIndexH=buffer[5];BYTE FIFO_SendLen;FIFO_SendLen=FIFO_wLengthL;if(FIFO_SendLen==0x01)GetCurMute();else if(FIFO_SendLen==0x02)GetCur_Volume();elseSTALL|=0x01;}void GetCur_Mute(BYTE *buffer){if(FIFO_wIndexH==0x02)GetCur_Mute_Speaker();else if(FIFO_wIndexH==0x06)GetCur_Mute_Mic();elseSTALL|=0x01;}void GetCur_Mute_Mic(BYTE *buffer){if(bFlag_Mic_Mute==TRUE)buffer[0]=0x01;elsebuffer[0]=0x00;while(1){if(Check_Real_Cmd()==TRUE) return;if(FIFO0_WR_CHECK()&0x0f==0) continue;//未准备好elsebreak;}Write_FIFO(Fifo_0_Addr,0x01,buffer);}void GetCur_Mute_Speaker(BYTE *buffer){if(bFlag_Audio_Mute==TRUE)buffer[0]=0x01;elsebuffer[0]=0x00;while(1){if(Check_Real_Cmd()==TRUE) return;if(FIFO0_WR_CHECK()&0x0f==0) continue;//未准备好elsebreak;}Write_FIFO(Fifo_0_Addr,0x01,buffer);}void GetCur_Volume(BYTE *buffer){if(buffer[5]==0x02)//FIFO_wIndexHGetCur_Volume_Speaker();else if(buffer[5]==0x06)GetCur_Volume_Mic();elseSTALL|=0x01;}void GetCur_Volume_Mic(BYTE *buffer){buffer[0]=0x00;buffer[1]=PGA_CTRL&0x3f;while(1){if(Check_Real_Cmd()==TRUE) return;if(FIFO0_WR_CHECK()&0x0f==0) continue;//未准备好else break;}Write_FIFO(Fifo_0_Addr,0x02,buffer);}void GetCur_Volume_Speaker(BYTE *buffer,BYTE VolumeL_Save,BYTE VolumeH_Save){buffer[0]=VolumeH_Save;buffer[1]=VolumeL_Save;while(1){if(Check_Real_Cmd()==TRUE) return;if(FIFO0_WR_CHECK()&0x0f==0) continue;//未准备好else break;}Write_FIFO(Fifo_0_Addr,0x02,buffer);}//****************************************// Const String 常量//******************************************BYTE device_desc_table[]={//18 bytesWORD 0x0112 ,//descriptor type (device descriptor) , size of descriptor (18 bytes)WORD 0x0110 ,//USB spec release (ver 1.1)WORD 0x0000 ,//device sub-class , Communication device class WORD 0x0800 ,//bMaxPacketSize0 maximum packet size , bDeviceProtocolWORD 0x04D9 ,//vendor ID = 004D9HWORD 0x2851 ,//product version ID (Sample Device)WORD 0x0100 ,//product version ID Device Release CodeWORD 0x0201 ,//product string index , manufacturer string indexWORD 0x0103 ,//number of configurations , serial number string index }BYTE config_desc_table[]={//9 bytesWORD 0x0209 ,//descriptor type (config descriptor) , size of descriptor WORD 0x00D9 ,//total length of descriptor (D9 H=217 bytes)WORD 0x0104 ,//index of this configuration , 4 interfaceWORD 0x3F00 ,//configuration string indexWORD 0x3F80 ,//configuration attributes (bus supply)WORD 0x3FFA ,//maxpower (500ma)}工学（学科代码：08）是指工程学科的总称。