自己用 C51寫的串口通訊程序
/*定義為中斷方式串口處理*/
#define INTERSENDSTR
/*不為8032系列芯片 */ 
//#define CHIP_8032  
 
#include <absacc.h>
#include <reg51.h>
#include <string.h>
#include "err.h"
 
 
#ifdef INTERSENDSTR
unsigned char xdata sSendComBuf[256],sRecComBuf[256];
unsigned char data bOut,bIn,bSout,bSin;
#else
#define DEFSENDCHAR TI=0;SBUF=ACC;while(!TI);TI=0;
#endif
//bps設置 9600 就是 PSetBps(96)（11.0592Mhz） 
 
unsigned char  PSetBps(unsigned int bps) SMALL
{
unsigned int t1;
unsigned char t2;
#ifdef INTERSENDSTR
/*如果使用中斷方式發送數據,必須等待發送數據完畢才能更換波特率 */
while(bSin!=bSout)
{
;
}
ES=0;
#endif 
 
#ifdef CHIP_8032
if(3456%bps)
{
return ERR_SET_BPS;
}
t1=3456/bps;
t1--;t1=~t1;
RCAP2H=t1/256;RCAP2L=t1;
T2MOD=0x00;
/*使用定時器 2 做波特率發生器 */
T2CON=0x34;/*TF2=0;EXF2=0;RCLK=1;TCLK=1;EXEN2=0;TR2=1;C/T2=0;CP/RL2=0
*/
#else
t1=576/bps;
if((576%bps)||((t1==0))||(t1>=2*256)) 
{
return ERR_SET_BPS;
}
if(t1>256)
{
PCON=00;
t2=256-(288/bps);
}
else
{
PCON=0x80;
t2=256-t1;
}
TH1=t2;TL1=t2;
TR1=1;
#endif 
/*模式3*/
SM0=0;
RI=0;TI=0;
REN=1;
SM1=1;
SM2=1;
#ifdef INTERSENDSTR  
bOut=bIn;
bSout=bSin;
ES=1;
#endif 
return OK;
}
void PSendChar(unsigned char ch) SMALL
{
 
#ifdef INTERSENDSTR
unsigned char tch;
 
tch=bSin+1;
while(tch==bSout)
{
;
}
sSendComBuf[bSin]=ch;
ES=0;
if((bSout==bSin))
{
SBUF=sSendComBuf[bSin];
bSin++;
}
else
{
bSin++;                
}
ES=1;
#else 
ACC=ch;
DEFSENDCHAR;
#endif 
}
unsigned char PGetChar() SMALL
{
unsigned char ch;
#ifdef   INTERSENDSTR
ch=sRecComBuf[bOut];
bOut++;
return ch;
#else
ch=SBUF;
RI=0;
#endif 
}
bit PCharInCom() SMALL
{
#ifdef   INTERSENDSTR
if(bIn!=bOut)
{
return 1;
}
return 0;
#else
return RI;
#endif
}
void PSendString(unsigned char *st) SMALL
{
while(*st)
{
PSendChar(*st);
st++;
}
}
void PSendArray(unsigned char  *st,unsigned int  len) SMALL
{
unsigned int ii;
for(ii=0;ii<len;ii++)
{
PSendChar(st[ii]);
}
}
#ifdef   INTERSENDSTR
void PSerialInt() interrupt 4
{
if(RI) 
{
sRecComBuf[bIn]=SBUF;
bIn++;
RI=0;
}
if(TI)
{
TI=0;
if(bSout!=bSin)
{
bSout++;
}
if(bSout!=bSin)
{
SBUF=sSendComBuf[bSout];
}
}
}
#endif