pascal.c

AT91所有开发板的资料 AT91所有开发板的资料

/****************************************************************
 *
 * ARM Strategic Support Group
 * 
 ****************************************************************/

/****************************************************************
 *
 *	Module		: pascal.c
 *	Description	: Writes out a Pascal's triangle using
 *			  	  semi-hosting and non-embedded libraries.
 *				  This program is used as a basic confidence 
 *				  test for the board.
 *	Platform	: Evaluator7T
 *  Tool Chain	: ARM Developer Suite 1.0
 * 	Status		: Complete
 * 	History		: 
 *
 *					980504 Andrew N. Sloss
 *					- create for AEB-1
 *				
 *				  	990422 Andrew N. Sloss				
 *					- ported to Evaluator7T
 *
 *	Notes		:
 *
 *			     Limited to a depth of 6, since the
 *			     output routines only work with single 
 *               digit numbers... 
 *
 ****************************************************************/

/****************************************************************
 * IMPORT
 ****************************************************************/

#include <stdio.h>
#include "led.h"

/****************************************************************
 * MACROS
 ****************************************************************/

// none...

/****************************************************************
 * DATATYPES
 ****************************************************************/

// none...

/****************************************************************
 * ROUTINES
 ****************************************************************/

/* -- pascal_generator ------------------------------------------
 *
 * Description 	: Generates the PASCAL triangle numbers
 * Tool Chain	: ADS 1.0
 * Parameters  	: int n - level 
 *		          int i - row
 * Return	    : int - calculated PASCAL triangle number...
 * Notes	    : A recursive function. Note recursive functions
 *		  	      are dangerous in embedded systems, which 
 *				  require deterministic stack...
 *
 */

int pascal_generator (int n, int i)
{
	LED_2_OFF;
	LED_2_ON;

    	if (i == 1 || i == n) return 1;
	
    	return pascal_generator(n-1,i-1) + pascal_generator(n-1,i);
}

/* -- pascal_triangle ------------------------------------------
 * 
 * Descriptions	: Builds the complete PASCAL's triangle.
 *
 * Parameters	: int d - depth
 * Return		: none...
 * Notes		: 
 *
 */

void pascal_triangle (int depth)
{
int 	i,j,s;

	LED_3_OFF;
    
	for (j = 1; j < depth; j++) {
        	printf("\n\t\t");

        	for ( s = depth-j; s > 0; s-- ) {
			putchar (' ');
		}

        	for (i = 1; i <= j; i++) {
        	printf("%d ", pascal_generator(j, i));
        	}        
    	}

	putchar ('\n');

	LED_3_ON;
}
   
/* -- pascal_init ----------------------------------------------
 *
 * Description	: initialize the LED on the Evaluator7T board
 *
 * Parameters	: none...
 * Return		: none...
 * Notes		: none...
 *
 */

void pascal_init (void)
{
	LED_1_OFF;
	LED_2_ON;
	LED_3_ON;
	LED_4_ON;
}

/* -- main -----------------------------------------------------
 *
 * Description	: entry point
 * 
 * Parameters	: none...
 * Return		: int
 * Notes		: none...
 *
 */

int main (void)
{
    printf( "hello, liming! " );
//return 1;
//	pascal_init();

//	LED_4_OFF;

  //      printf ("\n\t*** Pascal's Triangle *** \n\n");
  //      pascal_triangle (6);

	LED_4_ON;
	
//	printf ("\n");
//	printf ("**************************************************\n");
//	printf ("** NOTE: Reset the Board and Close the Debugger **\n");
//	printf ("**************************************************\n");

	return 1;
}

/****************************************************************
 * End of Pascal.c
 ****************************************************************/