SD_card.rar_SD card C51_c51 SD Spi_c51 spi sd_sd card_write sd c

#include<reg52.h> #define uchar unsigned char #define uint8 unsigned char #define ulong unsigned long #define TRUE 0xff #define FALSE 0x00 #define SD_RESET 0x40 #define SD_INIT 0x00 #define INIT_CMD1_ERROR 0x00 sbit PIN_CLK= P0^1; sbit PIN_CS=P0^2; sbit PIN_WR=P0^0; sbit PIN_RD=P0^3; #define SD_Disable() PIN_CS=1 //片选关 #define SD_Enable() PIN_CS=0 //片选开 //SD卡控制相关函数 void SPI_WBYTE(uchar val);//往SD卡写入1字节 uchar SPI_RBYTE(void);//从SD卡读出1字节 uchar SdResponse();//读SD卡响应 void SdCommand(uchar command, ulong argument, uchar CRC);//写入命令 //串口辅助控制相关函数 void BCOM_IniCom();//串口初始化 void delay1 (int ms) { int i,j; for(i=0;i<ms;i++) for(j=0;j<123;j++); } //往SD卡写入1字节 void SPI_WBYTE(uchar val) { uchar i = 0; for(i=8;i;i--) { PIN_CLK = 0; PIN_WR = (val&0x80); val<<=1; PIN_CLK = 1; } PIN_WR = 1; //PIN_CLK = 0; } //从SD卡读出1字节 uchar SPI_RBYTE(void) { uchar n = 0; uchar i = 0; PIN_RD = 1; for(i=8;i;i--) { PIN_CLK=0; PIN_CLK=1; n<<=1; if(PIN_RD) n|=1; } return n; } //读SD卡响应 uchar SdResponse() { uchar i=0,response; while(i<=8) { response=SPI_RBYTE(); if(response==0x00) break; if(response==0x01) break; i++; } return response; } //写入命令 void SdCommand(uchar command, ulong argument, uchar CRC) { SPI_WBYTE(command|0x40); SPI_WBYTE(((unsigned char *)&argument)[0]); SPI_WBYTE(((unsigned char *)&argument)[1]); SPI_WBYTE(((unsigned char *)&argument)[2]); SPI_WBYTE(((unsigned char *)&argument)[3]); SPI_WBYTE(CRC); } //SD卡初始化 uchar SdInit(void) { int delay=0, trials=0; uchar i; uchar res=0x01; SD_Disable(); for(i=0;i<=9;i++) SPI_WBYTE(0xff); SD_Enable(); //Send Command 0 to put MMC in SPI mode SdCommand(0x00,0,0x95); res=SdResponse(); SBUF = res; delay1(10); if(res!=0x01) { return 0; } while(res==0x01) { SD_Disable(); SPI_WBYTE(0xff); SD_Enable(); SdCommand(0x01,0x00ffc000,0xff); res=SdResponse(); } SD_Disable(); SPI_WBYTE(0xff); return 1; } /* ********************************************************************** 函数名: BCOM_IniCom 参数: 无 返回值: 无 作用: 初始化串口，波特率为9600bps ********************************************************************** */ void BCOM_IniCom() { SCON = 0x50; //定义为方式1，可变波特率发送数据 PCON = 0x80; //波特率系数，使波特率加倍 TMOD = 0x20; //使用定时器T1，自动重装8位计数器 TH1 = 0xf4; TL1 = 0xf4; //9600波特率通讯 TR1 = 1; //定时器1运行控制位 IE = 0x90; //允许串口中断 EA = 1; //中断允许 } //串口接收中断函数 void serial () interrupt 4 using 3 { if (RI) RI = 0 ; else if (TI) TI=0; } void main (void) { //uchar i; P0 =0x00; PIN_CS = 0 ; PIN_RD = 1; PIN_WR = 0; PIN_CLK = 0; //初始化串口 BCOM_IniCom(); delay1(10); EA=1; ES=1; // SdInit(); PIN_CS = 0 ; while(1) { delay1(10); } }