软件模拟ＳＰＩ总线读写，速度Ｎｏ．１，请高手打檑台

呱呱

软件模拟ＳＰＩ总线读写，速度Ｎｏ．１，请高手打檑台 [复制链接]

最近在调试我设计的ＭＰ３，用到ＳＰＩ读写ＳＤ卡和向ＶＳ１００３Ｂ发送数据，因为ＭＰ３对数据流速度相当敏感，遂对软件ＳＰＩ进行了优化，目前已能流畅播放了。 我的ＳＰＩ总线单字节读写函数如下，自认为速度最快了，已至极致，纵然汇编实现，也只能打个平手，５１高手请指正。 #include "..\inc\includes.h" sbit c_SPI_SI = P1^5; sbit c_SPI_SO = P1^6; sbit c_SPI_CLK = P1^7; #define Macro_Set_SI_High() c_SPI_SI = 1 #define Macro_Set_SI_Low() c_SPI_SI = 0 #define Macro_Set_CLK_High() c_SPI_CLK = 1 #define Macro_Set_CLK_Low() c_SPI_CLK = 0 /* //----------------标准C语言版----------------------------------------- //可移植性好，易读，易移植 uint8 SD_SPI_ReadByte(void) { uchar ucReadData; uchar ucCount; ucReadData = 0; Macro_Set_SI_High(); for(ucCount=0; ucCount<8; ucCount++) { ucReadData <<= 1; Macro_Set_CLK_Low(); Macro_Set_CLK_High(); if(c_SPI_SO) { ucReadData |= 0x01; } } return(ucReadData); } void SD_SPI_WriteByte(uint8 ucSendData) { uchar ucCount; uchar ucMaskCode; ucMaskCode = 0x80; for(ucCount=0; ucCount<8; ucCount++) { Macro_Set_CLK_Low(); if(ucMaskCode & ucSendData) { Macro_Set_SI_High(); } else { Macro_Set_SI_Low(); } Macro_Set_CLK_High(); ucMaskCode >>= 1; } } */ //-------------------------标准优化版ＳＰＩ读写函数--------- uchar bdata ucReadData; sbit ReadData_Bit0 = ucReadData^0; sbit ReadData_Bit1 = ucReadData^1; sbit ReadData_Bit2 = ucReadData^2; sbit ReadData_Bit3 = ucReadData^3; sbit ReadData_Bit4 = ucReadData^4; sbit ReadData_Bit5 = ucReadData^5; sbit ReadData_Bit6 = ucReadData^6; sbit ReadData_Bit7 = ucReadData^7; uchar bdata ucWriteData; sbit WriteData_Bit0 = ucWriteData^0; sbit WriteData_Bit1 = ucWriteData^1; sbit WriteData_Bit2 = ucWriteData^2; sbit WriteData_Bit3 = ucWriteData^3; sbit WriteData_Bit4 = ucWriteData^4; sbit WriteData_Bit5 = ucWriteData^5; sbit WriteData_Bit6 = ucWriteData^6; sbit WriteData_Bit7 = ucWriteData^7; uint8 SD_SPI_ReadByte(void) { //初始化SI引脚状态 Macro_Set_SI_High(); //Bit7 Shift Out Macro_Set_CLK_Low(); Macro_Set_CLK_High(); ReadData_Bit7 = c_SPI_SO; //Bit6 Shift Out Macro_Set_CLK_Low(); Macro_Set_CLK_High(); ReadData_Bit6 = c_SPI_SO; //Bit5 Shift Out Macro_Set_CLK_Low(); Macro_Set_CLK_High(); ReadData_Bit5 = c_SPI_SO; //Bit4 Shift Out Macro_Set_CLK_Low(); Macro_Set_CLK_High(); ReadData_Bit4 = c_SPI_SO; //Bit3 Shift Out Macro_Set_CLK_Low(); Macro_Set_CLK_High(); ReadData_Bit3 = c_SPI_SO; //Bit2 Shift Out Macro_Set_CLK_Low(); Macro_Set_CLK_High(); ReadData_Bit2 = c_SPI_SO; //Bit1 Shift Out Macro_Set_CLK_Low(); Macro_Set_CLK_High(); ReadData_Bit1 = c_SPI_SO; //Bit0 Shift Out Macro_Set_CLK_Low(); Macro_Set_CLK_High(); ReadData_Bit0 = c_SPI_SO; return(ucReadData); } void SD_SPI_WriteByte(uint8 ucSendData) { ucWriteData = ucSendData; //Bit7 Shift Out To SD Card Macro_Set_CLK_Low(); c_SPI_SI = WriteData_Bit7; Macro_Set_CLK_High(); //Bit6 Shift Out To SD Card Macro_Set_CLK_Low(); c_SPI_SI = WriteData_Bit6; Macro_Set_CLK_High(); //Bit5 Shift Out To SD Card Macro_Set_CLK_Low(); c_SPI_SI = WriteData_Bit5; Macro_Set_CLK_High(); //Bit4 Shift Out To SD Card Macro_Set_CLK_Low(); c_SPI_SI = WriteData_Bit4; Macro_Set_CLK_High(); //Bit3 Shift Out To SD Card Macro_Set_CLK_Low(); c_SPI_SI = WriteData_Bit3; Macro_Set_CLK_High(); //Bit2 Shift Out To SD Card Macro_Set_CLK_Low(); c_SPI_SI = WriteData_Bit2; Macro_Set_CLK_High(); //Bit1 Shift Out To SD Card Macro_Set_CLK_Low(); c_SPI_SI = WriteData_Bit1; Macro_Set_CLK_High(); //Bit0 Shift Out To SD Card Macro_Set_CLK_Low(); c_SPI_SI = WriteData_Bit0; Macro_Set_CLK_High(); }

呱呱

奉上测试程序及测试记录 void TestSD_SPIFunc(void) { uchar ucCount; uchar ucReadData; ucCount = 0; //开始 for(ucCount=0; ucCount<10; ucCount++) { SPI_TransferByte(0x88); //用C语言实现的写字节机器周期数为188 //用C51的bData变量，采用位指令直接传送操作，共用机器机器49 } for(ucCount=0; ucCount<50; ucCount++) { ucReadData = SPI_ReadByte(); //用C语言实现的SPI读字节机器赌周期为154 //自用C51的bData变量，采用位指令操作读字节机器周期为49 } ucCount= 88; //结束 SD_read_sector(0,Page_Buf); }

呱呱

每移一位占用４个机器周期 很奇怪５１指令，读一个位到Ｃ用一个机器周期，而将Ｃ输出到位地址用２个机器周期，而且必须通过Ｃ中转。 ＭＯＶ　C,Bit 周期１，编码10100010 MoV bit,C 周期２，编码10010010

星哥

看不懂～～～～～～～～～～～～

dswybs

最好把你程序的格式排版一下，这么弄还没看就眼晕了。

yjj

恩，哈哈。我也晕了