- #include<reg52.h>
- #include<stdio.h>
- volatile unsigned char UartIsSending;//volatile防止该变量所在语句被优化，问：静态的不行？全局变量不行？
- char putchar (char ucWriteData)//函数重写
- {
- SBUF=ucWriteData;
- UartIsSending=1;
- while(UartIsSending);
- return ucWriteData;
- }
- volatile unsigned char UartIsSending;
- void UartIsr(void) interrupt 4
- {
- if(TI) //发送中断
- {
- UartIsSending=0;
- TI=0;
- }
- if(RI) //接收中断
- {
- RI=0;
- }
- }
- void serial_init ()
- {
- SCON = 0x50;
- TMOD |= 0x20;
- TH1 = 0xf3;
- TL1 = 0xf3;
- TR1 = 1;
- ES=1;
- }
- void Delay(void)
- {
- unsigned char ucDelayCount;
- for(ucDelayCount=0; ucDelayCount<0xFF; ucDelayCount++)
- {
- ;
- }
- }
- void main(void)
- {
- serial_init();
- EA = 1;
- while(1)
- {
- putchar('8');
- putchar('\n');
- Delay();
- printf("welcome to 21ic \n");
- }
- }
| 
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