51单片机驱动TFT彩屏驱动程序+SD卡

#include "MMC.h" bit Init_Flag; //Set it to 1 when Init is processing. bit card_type; //uchar csd_data[16]; //uchar cid_data[16]; unsigned char CMD[] = {0x40,0x00,0x00,0x00,0x00,0x95};//CMD0 /********************************************************** 延时子函数 **********************************************************/ void delay(unsigned int time) { while(time--); } /********************************************************** us延时子程序 (4.34us) **********************************************************/ void delayNOP() { _nop_(); _nop_(); _nop_(); _nop_(); } /************************************************************ 卡端口初始化 ************************************************************/ void MMC_Port_Init() { SPI_CLK=1; SPI_DO =1; SPI_CS=1; } //**************************************************************************** //Routine for sending a byte to MMC/SD-Card //write a byte //**************************************************************************** void Write_Byte_MMC(uchar value) { unsigned char i; for (i=0;i<8;i++) { if (value&0x80) SPI_DI=1; //Send bit by bit(MSB First) else SPI_DI=0; SPI_CLK=0; //Clock low if(Init_Flag) delayNOP(); SPI_CLK=1; //Clock High if(Init_Flag) delayNOP(); value <<=1; } } //**************************************************************************** //Routine for reading a byte from MMC/SD-Card //Software SPI //**************************************************************************** unsigned char Read_Byte_MMC() { unsigned char temp=0; unsigned char i; SPI_DO=1; for (i=0;i<8;i++) //MSB First { SPI_CLK=0; //Clock Low if(Init_Flag) delayNOP(); SPI_CLK=1; //Clock High if(Init_Flag) delayNOP(); temp=(temp<<1)|SPI_DO; //read mmc data out pin } return (temp); } //**************************************************************************** //Send a Command to MMC/SD-Card //Return: the second byte of response register of MMC/SD-Card //**************************************************************************** unsigned char Write_Command_MMC(unsigned char *CMD) { unsigned char tmp; unsigned char i; //set MMC_Chip_Select to high (MMC/SD-Card disable) SPI_CS=1; //send 8 Clock Impulse Write_Byte_MMC(0xFF); //set MMC_Chip_Select to low (MMC/SD-Card active) SPI_CS=0; //send 6 Byte Command to MMC/SD-Card for (i=0;i<0x06;i++) { Write_Byte_MMC(*CMD++); } i = 0; //get 16 bit response Read_Byte_MMC(); //read the first byte,ignore it. do { //Only last 8 bit is used here.Read it out. tmp = Read_Byte_MMC(); i++; } while((tmp==0xff)&&(i<100)); return(tmp); } //********************************************************** //Routine for Init MMC/SD card(SPI-MODE) unsigned char MMC_Init() //********************************************************** { unsigned char temp; unsigned char i; MMC_Port_Init(); //Init SPI port delay(200); Init_Flag=1; //Set the init flag for (i=0;i<0x0f;i++) { Write_Byte_MMC(0xff); //send 74 clock at least!!! } //Send Command CMD0 to MMC/SD Card i = 0; do { //retry 200 times to send CMD0 command temp=Write_Command_MMC(CMD); i++; if(i >= 200) { //time out return(INIT_CMD0_ERROR); //CMD0 Error! } } while(temp!=1); i = 0; do{ CMD[0] = 0x77; //CMD55命令 temp = Write_Command_MMC(CMD); //先发送 CMD55 if(temp == 0x01) //如果有反应 { CMD[0] = 0x69; //ACMD41命令 temp = Write_Command_MMC(CMD); //发送CMD41进行激活 if(temp == 0x00) //激活成功就是SD卡 { card_type =1; //SD } } else //如果发送CMD55无反应，改发送CMD1 { CMD[0] = 0x41; //CMD1命令 CMD[5] = 0xFF; temp = Write_Command_MMC(CMD); //发送CMD1进行激活 if(temp == 0x00) //激活成功就是MMC卡 { card_type =0; //MMC } } i++; if(i >= 200) { return(INIT_CMD1_ERROR); //CMD1 Error! } }while(temp != 0x00); // MMC和SD卡激活后的返回值均为0x00 Init_Flag=0; //Init is completed,clear the flag SPI_CS=1; //set MMC_Chip_Select to high // wr_string(0,2," INIT SUCCESS "); return(0); //All commands have been taken. } //************************************************************ //Routine for reading data Registers of MMC/SD-Card //Return 0 if no Error. //************************************************************ unsigned char MMC_Read_Block(uchar *CMD,uchar *Buffer,uint Bytes) { unsigned int i; unsigned char temp; //Send Command CMD to MMC/SD-Card i = 0; do { //Retry 100 times to send command. temp=Write_Command_MMC(CMD); i++; if(i == 100) { return(READ_BLOCK_ERROR); //block write Error! } } while(temp!=0); //Read Start Byte form MMC/SD-Card (FEh/Start Byte) while (Read_Byte_MMC()!=0xfe) ; //Write blocks(normal 512Bytes) to MMC/SD-Card for (i=0;i<Bytes;i++) { *Buffer++ = Read_Byte_MMC(); } Read_Byte_MMC();//CRC - Byte Read_Byte_MMC();//CRC - Byte SPI_CS=1; return(0); } //************************************************************ //Routine for reading CSD Registers from MMC/SD-Card (16Bytes) //Return 0 if no Error. //Command for reading CSD Registers //************************************************************ unsigned char Read_CSD_MMC(unsigned char *Buffer) { unsigned char temp; CMD[0]=0X49; //CMD9:读CSD寄存器. CMD[5]=0XFF; temp=MMC_Read_Block(CMD,Buffer,16); //read 16 bytes return(temp); } //************************************************************ //Routine for reading CID Registers from MMC/SD-Card (16Bytes) //Return 0 if no Error. //Command for reading CID Registers //************************************************************ unsigned char Read_CID_MMC(unsigned char *Buffer) { unsigned char temp; CMD[0]=0X4A; //CMD10:读CID寄存器. CMD[5]=0XFF; temp=MMC_Read_Block(CMD,Buffer,16); //read 16 bytes return(temp); } /**********************************************************/