with which crystal and pll setting can get 55 mhz for at91

Development Boards MicroMod
1

with which crystal and pll setting can get 55 mhz speed for at91sam7?

2

nader:
with which crystal and pll setting can get 55 mhz speed for at91sam7?

Why not read the data sheet?

Leon

3

leon_heller:

nader:
with which crystal and pll setting can get 55 mhz speed for at91sam7?

Why not read the data sheet?

Leon

Because it's easier to ask THREE (well, at least - I've only seen it at three so far) different message boards.

I hate people like this.

4

There are no PLL settings for 55Mhz with a 18432Khz crystal. I wrote a little program for calculating PLL settings, here it is (Note, the frequency must be twice the desired, since the clock requires 2 cycles for lock, just like the old days):

#include <stdio.h>
#include <math.h>
 
int main(void)
{
        float i,j,k,l;
 
        j=18432;
        k=96000;
 
        for(i=1;i<256;i++) {
                if(fmod(j,i)==0.0) {
                        for (l=1;l<2048;l++) {
                                if ((j/i)*l==k) {
                                        printf ("%7.0f / %7.0f * %7.0f = %7.0f\n",j,i,l,k);
                                }
                        }
                }
        }
 
        return 0;
}