7-2.c

一些简单的c51程序

#include <REG52.H>              
#include <stdio.h>              
#include <float.h>

#ifdef MONITOR51                        // 假如使用使用MONITOR51 
char code reserve [3] _at_ 0x23;         
#endif                                  //结束IF 
                                        

#define LOWER 0                          //表的下限
#define UPPER 300                        //表的上限
#define STEP 20                          //步长

//打印华氏-摄氏温度对照表
void main (void) {

int fahr;
#ifndef MONITOR51
    SCON  = 0x50;		        
    TMOD |= 0x20;               
    TH1   = 221;                
    TR1   = 1;                                           
    TI    = 1;                  
#endif

	for ( fahr = LOWER; fahr <= UPPER; fahr = fahr + STEP )
	printf ( "%3d %6.1f\n", fahr, (5.0 / 9.0) * (fahr - 32 ) );

	while (1) {};
}