ch4-6.c

单片机接口技术(C51版)例程源代码

#include<stdio.h> 
#include<reg51.h>
     int i=10; 
     int main() 
     { 
          int i=1; 
#ifndef MONITOR51
    SCON  = 0x50;		        /* SCON: mode 1, 8-bit UART, enable rcvr      */
    TMOD |= 0x20;               /* TMOD: timer 1, mode 2, 8-bit reload        */
    TH1   = 221;                /* TH1:  reload value for 1200 baud @ 16MHz   */
    TR1   = 1;                  /* TR1:  timer 1 run                          */
    TI    = 1;                  /* TI:   set TI to send first char of UART    */
#endif
          printf("%d\t  ", i); 
          { 
               int i=2; 
               printf("%d\t   ", i); 
               { 
                    extern i; 
                    i+=1; 
                    printf("%d\t   ", i); 
               } 
               printf("%d\t   ", ++i); 
          } 
          printf("%d\n", ++i); 
          return 0; 
     }