Question

单片机如何发送多字节数据

#include<reg51.h>
unsigned int addr,a;
unsigned long int key;
void send()
{
SBUF=key;
while(TI==0);
TI==0;
}
void main(void)
{
for (a=0; a<16; a++)
{
addr=0x00;
key=0x0000;
P1=addr;
addr=addr+0x11;
if(P3^4==1)
{
key=key|(1<<a);
}
if(P3^5==1)
{
key=key|(1<<(a+16));
}
}
TMOD=0X20;
SCON=0X50;
TH1=0Xfc;
TL1=0Xfc;
PCON=0X00;
TR1=1;

send();
}

这里KEY是32位的
要把KEY都发出去 void send()怎么写

Answer 1

void send()
{
unsigned char dat,i;
for(i=0;i<4;i++)
{
dat=(char)key&0x000000ff;
SBUF=dat;
while(TI==0);
TI=0;
key=key>>8;
}
}