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- #include<reg51.h>
- #define uchar unsigned char
- #define SLAVE 0x00
- #define BN 16
- uchar idata tdata[16];
- uchar idata rdata[16];
- bit trdy;
- bit rrdy;
- void main(void)
- {
- TMOD=0x20; //定時(shí)器T1為模式2
- TL1=0xfd; //定時(shí)器初值
- TH1=0xfd;
- PCON=0x00;
- TR1=1;
- SCON=0xf0; //串行口方式3
- ES=1;EA=1; //開串行口中斷
- while(1){trdy=1;rrdy=1;} //準(zhǔn)備好發(fā)送和接收
- }
- void slave(void) interrupt 4 using 1
- {
- void str(void);
- void sre(void);
- uchar a;
- RI=0; //關(guān)串行口中斷
- ES=0;
- if(SBUF!=SLAVE){ES=1;goto reti;} //非本機(jī)地址，繼續(xù)監(jiān)聽
- SM2=0; //取笑監(jiān)聽狀態(tài)
- SBUF=SLAVE; //發(fā)回從機(jī)地址
- while(TI!=1);TI=0;
- while(RI!=1);RI=0;
- if(RB8==1){SM2=1;ES=1;goto reti;} //確認(rèn)地址不符，從機(jī)復(fù)位
- a=SBUF; //接收命令
- if(a==1){ //從機(jī)接收主機(jī)的數(shù)據(jù)
- if(rrdy==1) SBUF=0x01; //接收準(zhǔn)備好，發(fā)回0x01
- else
- SBUF=0x00;
- while(TI!=1);TI=0;
- while(RI!=1);RI=0;
- if(RB8==1){SM2=1;ES=1;goto reti;}
- sre(); //接收數(shù)據(jù)
- }
- else
- {
- if(a==0x02) //從機(jī)向主機(jī)發(fā)送數(shù)據(jù)
- {
- if(trdy==1) SBUF=0x02; //發(fā)送準(zhǔn)備好
- else
- SBUF=0x00;
- while(TI!=1);TI=0;
- while(RI!=1);RI=0;
- if(RB8==1){SM2=1;ES=1;goto reti;}
- str( ); //發(fā)送數(shù)據(jù)
- }
- else
- {
- SBUF=0x80; //命令非法
- while(TI!=1);TI=0;
- SM2=1;ES=1; //恢復(fù)監(jiān)聽
- }
- }
- reti:;
- }
- void str(void) //發(fā)送數(shù)據(jù)函數(shù)
- {uchar p,i;
- trdy=0;
- do{p=0; //初始校驗(yàn)和為0
- for(i=0;i<BN;i++)
- {SBUF=tdata[i]; //發(fā)送數(shù)據(jù)
- p+=tdata[i];
- while(TI!=1);TI=0;
- }
- SBUF=p; //發(fā)送校驗(yàn)和
- while(TI!=1);TI=0;
- while(RI!=1);RI=0;
- }while(SBUF!=0); //主機(jī)接收不正確，重新發(fā)送
- SM2=1;ES=1;
- }
- void sre(void) //接收數(shù)據(jù)函數(shù)
- {uchar p,i;
- rrdy=0;
- while(1)
- {p=0; //初始化校驗(yàn)和為0
- for(i=0;i<BN;i++)
- {while(RI!=1);RI=0;
- tdata[i]=SBUF; //接收數(shù)據(jù)
- p+=rdata[i];
- }
- while(RI!=1);RI=0;
- if(SBUF==p){SBUF=0x00;break;} //校驗(yàn)和相同，發(fā)00H
- else{
- SBUF=0xFF;while(TI!=1);TI=0; //校驗(yàn)和不同，發(fā)FFH，重新接收
- }
- }
- SM2=1;ES=1;
- }
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