main.c

一个小的嵌入式os

//====================================================================
//filename		:main.c
//description	:set the pll.get the mdiv and the pdiv,the sdiv 
//				 always is "1"
//author		:kaka,[e-mail] 
//				The PLL set for S3C44B0X
//====================================================================




#include <stdio.h>
#define f_out 66				//change the value for yourself
								//the frequency out that you want
#define f_in  8					//the frequency in 
								//change the value for yourself


int mdiv,pdiv;
void main(void)
{

float f,a,b,flag,fout,fin;
fout=f_out;
fin=f_in;
a=(fin/2-2);
b=(fin-2);
printf("<----------------------->\n");
printf("<---PLL set for 44B0X--->\n");
printf("<---	Author kaka  --->\n");
printf("<[e-mail]--->\n");
printf("<----------------------->\n");
printf("PLLout is=%fMhz,Fin is=%fMhz \n",fout,fin);

printf("========================================== \n");

while(f!=fout)
{
	if((a<pdiv) &(pdiv<b))
	{
		flag=1;
		
	}
	pdiv++;
	
	if(flag==1)
	{
		for(mdiv=0;mdiv<1024;mdiv++)
		{
			f=((mdiv+8)*fin)/((pdiv+2)*2);

			if((int)f==fout) 
			
			{
				printf("Mdiv=%d,Pdiv=%d ",mdiv,pdiv);


				printf("The PLLout is %fMhz \n",f);
				printf("========================================== \n");
			}
		}	
	
	}
	flag=0;
	



}


while(1);

}