[原创]USB通信协议的理解-流程-描述.doc

原创USB通信协议的理解,流程,描述 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0 MISC|=0X00;/TX位置0; Delay_3us(); MISC|=0X01;/Set Request Delay_28us(); if(MISC&0X40!=0) FIFO_FLAG=0x0f;/READY if(MISC&0x80!=0) FIF0_FLAG&=0xf0;/Len0 Detected MISC&=0xfe;/clear REQ return 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0 MISC|=0X02;/TX位置0; Delay_3us(); MISC|=0X01;/Set Request Delay_28us(); if(MISC&0X40!=0) FIFO_FLAG=0x0f;/READY if(MISC&0x80!=0) FIF0_FLAG&=0xf0;/Len0 Detected MISC&=0xfe;/clear REQ return FIFO_FLAG;void Read_FIFO(BYTE *Fifo_Addr,BYTE Fifo_Size,BYTE *buffer) int i=0; MISC|=0x01;/Set Request for(i=0;iFifo_Size;i+) bufferi=Fifo_Addr0;/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 Requestvoid Write_FIFO(BYTE *Fifo_Addr,BYTE SendLenth,BYTE *buffer) int i=0; MISC|=0X01;/Set Request for(i=0;idata_start0)/请求的数据超出ROM数据 return; data_count=buffer6; if(MISC&0x40!=0)/是控制指令 return; if(data_count=0) Send_Hand_Shake(); return; /开始真正的control_read while(1) if(bFlag_RD_HTable=0)/Read Low Byte bFlag_RD_HTable=1; bufferi=(BYTE )*rom_dataptr;/取其低位 i+; data_count-;/全局变量,要发送的总长度 if(data_count8;/取其高位 rom_dataptr+;/将ROM指针前移 if(bufferi=0x3f) continue; else i+; if(data_count=0X81 0010 0000B if(temp&STALL=TRUE)/要检测的位置1 buffer0=1; else buffer0=0; buffer1=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; buffer0=USB_Configuration; FIFO_SendLen=0x01; while(1) if(Check_Real_Cmd()=TRUE) return; if(FIFO_WR_CHECK(0)&0x0f!=0)/Fifo Ready break; 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; buffer0=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=buffer3; BYTE nCmdIndex1; if(FIFO_wValueH=0x02)/set_output_report if(buffer4!=0x03)/check interface STALL|=0x01;/ENPOINT0 Error return; if(buffer6!=0x08)/FIFO_wLengthL,check length STALL|=0x01;/ENPOINT0 Error return; 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(buffer3=0x01)/MUTE_CONTROL MuteControl(); else if(buffer3=0x02)/VOLUME_CONTROL VolumeControl(); else STALL0|=0x01;BYTE MuteControl(BYTE *buffer) /21 01 00 01,if have more feature , the state must be modify! BYTE nCmdIndex1; if(buffer5=0x02)/FIFO_wIndexH,MuteControl_SetSpeaker(); nCmdIndex1=0x18; return nCmdIndex1; else if(buffer5=0x06)/MuteControl_SetMic(); nCmdIndex1=0x19; return nCmdIndex1; BYTE VolumeControl(BYTE *buffer) BYTE nCmdIndex1; if(buffer5=0x02)/FIFO_wIndexH,VolumeControl_SetSpeaker() nCmdIndex1=0x28; return nCmdIndex1; else ifbuffer5=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(buffer5=0x02)/FIFO_wIndexH GetMin_SetSpeaker(); else if(buffer5=0x06) GetMin_SetMic(); else STALL|=0X01;void GetMin_SetSpeaker(BYTE *buffer) buffer0=0x00; buffer1=0xe0;/Min_Volume 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)void GetMin_SetMic(BYTE *buffer) buffer0=0x00; buffer1=0x00;/MIC_Min_Volume 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)/*/ GetMax(): 获取各种最大信息的函数 / 包括Speaker,Mic/*void GetMax(BYTE *buffer) if(buffer5=0x02)/FIFO_wIndexH GetMax_SetSpeaker(); else if(buffer5=0x06) GetMax_SetMic(); else STALL0|=0x01;void GetMax_SetSpeaker(BYTE *buffer) buffer0=0x00; buffer1=0x0c;/Max_Volume 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)void GetMax_SetMic(BYTE *buffer) buffer0=0x00; buffer1=0x0c;/MIC_Max_Volume 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)/*/ GetRes(): / /*void GetRes(BYTE *buffer) buffer0=0x00; buffer1=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=buffer6; BYTE FIFO_wIndexH=buffer5; BYTE FIFO_SendLen; FIFO_SendLen=FIFO_wLengthL; if(FIFO_SendLen=0x01) GetCurMute(); else if(FIFO_SendLen=0x02) GetCur_Volume(); else STALL|=0x01;void GetCur_Mute(BYTE *buffer) if(FIFO_wIndexH=0x02) GetCur_Mute_Speaker(); else if(FIFO_wIndexH=0x06) GetCur_Mute_Mic(); else STALL|=0x01;void GetCur_Mute_Mic(BYTE *buffer) if(bFlag_Mic_Mute=TRUE) buffer0=0x01; else buffer0=0x00; 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,0x01,buffer);void GetCur_Mute_Speaker(BYTE *buffer) if(bFlag_Audio_Mute=TRUE) buffer0=0x01; else buffer0=0x00; 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,0x01,buffer);void GetCur_Volume(BYTE *buffer) if(buffer5=0x02)/FIFO_wIndexH GetCur_Volume_Speaker(); else if(buffer5=0x06) GetCur_Volume_Mic(); else STALL|=0x01;void GetCur_Volume_Mic(BYTE *buffer) buffer0=0x00; buffer1=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) buffer0=VolumeH_Save; buffer1=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 bytes WORD 0x0112 ,/descriptor type (device descriptor) , size of descriptor (18 bytes) WORD 0x0110 ,/USB spec release (ver 1.1) WORD 0x0000 ,/devi