main.c

time triggered 时间触发嵌入式系统的开发实例3

/*------------------------------------------------------------------*-

   Main.C (v1.00)

  ------------------------------------------------------------------

   Test program for pattern PORT I-O
 
   Illustrating the use of bitwise operators.


   COPYRIGHT
   ---------

   This code is from the book:

   PATTERNS FOR TIME-TRIGGERED EMBEDDED SYSTEMS by Michael J. Pont 
   [Pearson Education, 2001; ISBN: 0-201-33138-1].

   This code is copyright (c) 2001 by Michael J. Pont.
 
   See book for copyright details and other information.

-*------------------------------------------------------------------*/


#include <stdio.h>

void Display_Byte(const unsigned char);

/* ............................................................... */

int main()
   { 
   unsigned char x = 0xFE; 
   unsigned int y = 0x0A0B;
   
   printf("%-35s","x");
   Display_Byte(x); 
   
   printf("%-35s","1s complement [~x]");
   Display_Byte(~x);   
   
   printf("%-35s","Bitwise AND [x & 0x0f]");
   Display_Byte(x & 0x0f);
   
   printf("%-35s","Bitwise OR [x | 0x0f]");
   Display_Byte(x | 0x0f);
   
   printf("%-35s","Bitwise XOR [x ^ 0x0f]");
   Display_Byte(x ^ 0x0f);
   
   printf("%-35s","Left shift, 1 place [x <<= 1] ");
   Display_Byte(x <<= 1);
   
   x = 0xfe; /* Return x to original value */
   printf("%-35s","Right shift, 4 places [x >>= 4]");
   Display_Byte(x >>= 4);
                          
   printf("\n\n");
                          
   printf("%-35s","Display MS byte of unsigned int y");
   Display_Byte((unsigned char) (y >> 8));

   printf("%-35s","Display LS byte of unsigned int y");
   Display_Byte((unsigned char) (y & 0xFF));


   return 0;
   } 
   
/* --------------------------------------------------------------- */

void Display_Byte(const unsigned char Ch)
   {
   unsigned char i, c = Ch;
   unsigned char Mask = 1 << 7;  
   
   for (i = 1; i <= 8; i++)
      {
      putchar(c & Mask ? '1' : '0');
      c <<= 1;
      }          
      
   putchar('\n');   
   }

/*------------------------------------------------------------------*-
  ---- END OF FILE -------------------------------------------------
-*------------------------------------------------------------------*/