标题:
单片机串口显示来自SD卡的数据源程序
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作者:
hongniu
时间:
2015-6-23 16:56
标题:
单片机串口显示来自SD卡的数据源程序
#include <reg52.h>
#define uchar unsigned char
#define uint unsigned int
sbit p1_7=P1^7;
sbit CS=P2^0; //片选信号(低电平有效)
sbit DATEIN =P2^1;//主-从数据输入
sbit SCLK=P2^2;//时钟信号
sbit DATEOUT=P2^3;//从-主数据输出
uint btime;
uchar c;
unsigned char bdata dat;
sbit dat_0=dat^0;
sbit dat_1=dat^1;
sbit dat_2=dat^2;
sbit dat_3=dat^3;
sbit dat_4=dat^4;
sbit dat_5=dat^5;
sbit dat_6=dat^6;
sbit dat_7=dat^7;
bit is_init;//决定是否延时;
uchar lpp;
unsigned char fhz;//返回值
uchar fhz_buff; //读返回值中间量
unsigned char xdata tab[512];
void delay(uint time)
{ while(time)
time--;
}
//**********************************************
/*读sd卡子程序,无返回值,有参函数,参数为要写入DATEIN数据线的字节*/
void write(unsigned char wr_)// 写入一个字节SD卡
{
dat=wr_;
DATEIN=dat_7;
SCLK=0;
if(is_init)delay(200);
if(!is_init)delay(2);
SCLK=1;
if(is_init) delay(200);
if(!is_init)delay(2);
DATEIN=dat_6;
SCLK=0;
if(!is_init)delay(2);
if(is_init)delay(200);
SCLK=1;
if(is_init) delay(200);
if(!is_init)delay(2);
DATEIN=dat_5;
SCLK=0;
if(is_init)delay(200);
if(!is_init)delay(2);
SCLK=1;
if(is_init) delay(200);
if(!is_init)delay(2);
DATEIN=dat_4;
SCLK=0;
if(is_init)delay(200);
if(!is_init)delay(2);
SCLK=1;
if(is_init) delay(200);
if(!is_init)delay(2);
DATEIN=dat_3;
SCLK=0;
if(is_init)delay(200);
if(!is_init)delay(2);
SCLK=1;
if(is_init) delay(200);
if(!is_init)delay(2);
DATEIN=dat_2;
SCLK=0;
if(is_init)delay(200);
if(!is_init)delay(2);
SCLK=1;
if(is_init) delay(200);
if(!is_init)delay(2);
DATEIN=dat_1;
SCLK=0;
if(is_init)delay(200);
if(!is_init)delay(2);
SCLK=1;
if(is_init) delay(200);
if(!is_init)delay(2);
DATEIN=dat_0;
SCLK=0;
if(is_init)delay(200);
if(!is_init)delay(2);
SCLK=1;
if(is_init) delay(200);
if(!is_init)delay(2);
}
unsigned char read()// 读取一个字节SD卡
{
DATEOUT=1;
SCLK=1;
if(is_init)delay(200);
if(!is_init)delay(2);
SCLK=0;
if(is_init)delay(200);
if(!is_init)delay(2);
dat_7=DATEOUT;
SCLK=1;
if(is_init)delay(200);
if(!is_init)delay(2);
SCLK=0;
if(is_init)delay(200);
if(!is_init)delay(2);
dat_6=DATEOUT;
SCLK=1;
if(is_init)delay(200);
if(!is_init)delay(2);
SCLK=0;
if(is_init)delay(200);
if(!is_init)delay(2);
dat_5=DATEOUT;
SCLK=1;
if(is_init)delay(200);
if(!is_init)delay(2);
SCLK=0;
if(is_init)delay(200);
if(!is_init)delay(2);
dat_4=DATEOUT;
SCLK=1;
if(is_init)delay(200);
if(!is_init)delay(2);
SCLK=0;
if(is_init)delay(200);
if(!is_init)delay(2);
dat_3=DATEOUT;
SCLK=1;
if(is_init)delay(200);
if(!is_init)delay(2);
SCLK=0;
if(is_init)delay(200);
if(!is_init)delay(2);
dat_2=DATEOUT;
SCLK=1;
if(is_init)delay(200);
if(!is_init)delay(2);
SCLK=0;
if(is_init)delay(200);
if(!is_init)delay(2);
dat_1=DATEOUT;
SCLK=1;
if(is_init)delay(200);
if(!is_init)delay(2);
SCLK=0;
if(is_init)delay(200);
if(!is_init)delay(2);
dat_0=DATEOUT;
return (dat);
}
void restsd()//复位SD卡
{ uchar i;
uchar pcmd[6]={0x40,0x00,0x00,0x00,0x00,0x95};
is_init=1;
CS=1;
for(i=0;i<15;i++)
{
//120时钟
write(0xff);
}
CS=1;
write(0xff);//据说是提高兼容性
CS=0;//片选开
write( pcmd[0]);
write( pcmd[1]);
write( pcmd[2]);
write( pcmd[3]);
write( pcmd[4]);
write( pcmd[5]);
fhz=read();
for(;;)
{
fhz=read();
if(fhz==0x01)break;
}
CS=1;
write(0xff);
}
void initsd()//初始化
{
//
uchar pcmd[6]={0x41,0x00,0x00,0x00,0x00,0xff};//
//
CS=1;
write(0xff);//据说是提高兼容性
CS=0;//片选开
write( pcmd[0]);
write( pcmd[1]);
write( pcmd[2]);
write( pcmd[3]);
write( pcmd[4]);
write( pcmd[5]);
fhz=read();
for(;;)
{
fhz=read();
if(fhz==0x00)break;
}
CS=1;
write(0xff);
}
void readsd(unsigned long addstart)//读SD卡物理扇区
{ unsigned long sdbuff1,sdbuff2,sdbuff3,sdbuff4;
uint j,n;
uchar zh1,zh2,zh3,zh4;
sdbuff1=addstart;
sdbuff2=addstart;
sdbuff3=addstart;
sdbuff4=addstart;
zh1=(sdbuff1>>24)&0x000000ff;
zh2=(sdbuff2>>16)&0x000000ff;
zh3=(sdbuff3>>8)&0x000000ff;
zh4=sdbuff4&0x000000ff;
// uchar pcmd[6]={0x51,zh1,zh2,zh3,zh4,0xff};//原来这里是高地址字节在前地地址在后啊201012月14日逻辑扇区在253*512=0X0001fa00
CS=1;
write(0xff);//据说是提高兼容性
CS=0;//片选开
write( 0x51);
write( zh1);
write( zh2);
write( zh3);
write( zh4);
write( 0xff);
DATEOUT=1;
for(;;)
{
fhz=read();
if(fhz==0x00)break;
}
DATEOUT=1;
for(;;)
{
fhz=read();
if(fhz==0xfe)break;
}
DATEOUT=1;
n=0;
for(j=512;j;j--)
{
tab[n]=read();
n++;
}
fhz=read();
fhz=read();
CS=1;
write(0xff);
}
void InitUART(void)
{
TMOD = 0x20;
SCON = 0x50;
TH1 = 0xFD;
TL1 = TH1;
PCON = 0x00;
EA = 1;
ES = 1;
TR1 = 1;
}
void UARTInterrupt(void) interrupt 4
{
if(RI)
{
RI = 0;
//add your code here!
}
else
TI = 0;
}
void SendOneByte(unsigned char c)
{
SBUF = c;
while(!TI);
TI = 0;
}
void main()
{ unsigned long numb;
uint f;
uchar m;
InitUART(); //串口初始化
is_init=1;
restsd();
initsd();
is_init=0;//提高始终频率
p1_7=0;
p1_7=1;
btime=65536;
while(1)
{
SendOneByte(0x88);
numb=0x00420a00;
do
{
readsd(numb);//读物理扇区
for(;;)
{
m=tab[f];
SendOneByte(m);
f++;
if(f==512)break;//这里的F一定要定义成UNSIGNED INT行
}
SendOneByte(0xcc);
numb=(numb+0x200);
}
while(0x0044620!=numb);
EA=0;
ES = 0;
TR1 = 0;
while(1);
}
}
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