198 lines
6.5 KiB
C
198 lines
6.5 KiB
C
/*
|
|
* Program for finding M & N values for DPLLs
|
|
* To be run on Host PC
|
|
*
|
|
* (C) Copyright 2010
|
|
* Texas Instruments, <www.ti.com>
|
|
*
|
|
* Aneesh V <aneesh@ti.com>
|
|
*
|
|
* See file CREDITS for list of people who contributed to this
|
|
* project.
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License as
|
|
* published by the Free Software Foundation; either version 2 of
|
|
* the License, or (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
|
|
* MA 02111-1307 USA
|
|
*/
|
|
#include <stdlib.h>
|
|
#include <stdio.h>
|
|
typedef unsigned int u32;
|
|
#define MAX_N 127
|
|
|
|
/*
|
|
* get_m_n_optimized() - Finds optimal DPLL multiplier(M) and divider(N)
|
|
* values based on the reference frequency, required output frequency,
|
|
* maximum tolerance for output frequency etc.
|
|
*
|
|
* target_freq_khz - output frequency required in KHz
|
|
* ref_freq_khz - reference(input) frequency in KHz
|
|
* m - pointer to computed M value
|
|
* n - pointer to computed N value
|
|
* tolerance_khz - tolerance for the output frequency. When the algorithm
|
|
* succeeds in finding vialble M and N values the corresponding output
|
|
* frequency will be in the range:
|
|
* [target_freq_khz - tolerance_khz, target_freq_khz]
|
|
*
|
|
* Formula:
|
|
* Fdpll = (2 * M * Fref) / (N + 1)
|
|
*
|
|
* Considerations for lock-time:
|
|
* - Smaller the N, better lock-time, especially lock-time will be
|
|
* - For acceptable lock-times:
|
|
* Fref / (M + 1) >= 1 MHz
|
|
*
|
|
* Considerations for power:
|
|
* - The difference in power for different N values giving the same
|
|
* output is negligible. So, we optimize for lock-time
|
|
*
|
|
* Hard-constraints:
|
|
* - N can not be greater than 127(7 bit field for representing N)
|
|
*
|
|
* Usage:
|
|
* $ gcc clocks_get_m_n.c
|
|
* $ ./a.out
|
|
*/
|
|
int get_m_n_optimized(u32 target_freq_khz, u32 ref_freq_khz, u32 *m, u32 *n,
|
|
u32 tolerance_khz)
|
|
{
|
|
u32 min_freq = target_freq_khz - tolerance_khz;
|
|
u32 max_freq = target_freq_khz;
|
|
u32 freq, freq_old;
|
|
*n = 1;
|
|
while (1) {
|
|
*m = min_freq / ref_freq_khz / 2 * (*n) ;
|
|
freq_old = 0;
|
|
while (1) {
|
|
freq = ref_freq_khz * 2 * (*m) / (*n);
|
|
if (abs(target_freq_khz - freq_old) <=
|
|
abs(target_freq_khz - freq)) {
|
|
freq = freq_old;
|
|
(*m)--;
|
|
break;
|
|
}
|
|
(*m)++;
|
|
freq_old = freq;
|
|
}
|
|
if (freq >= min_freq && freq <= max_freq)
|
|
break;
|
|
(*n)++;
|
|
if ((*n) > MAX_N + 1) {
|
|
printf("ref %d m %d n %d target %d : ",
|
|
ref_freq_khz, *m, *n, target_freq_khz);
|
|
printf("can not find m & n - please consider"
|
|
" increasing tolerance\n");
|
|
return -1;
|
|
}
|
|
}
|
|
(*n)--;
|
|
printf("ref %d m %d n %d target %d locked %d\n",
|
|
ref_freq_khz, *m, *n, target_freq_khz, freq);
|
|
if ((ref_freq_khz / (*n + 1)) < 1000) {
|
|
printf("\tREFCLK - CLKINP/(N+1) is less than 1 MHz - less than"
|
|
" ideal, locking time will be high!\n");
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
void main(void)
|
|
{
|
|
u32 m, n;
|
|
printf("\nMPU - 2000000\n");
|
|
get_m_n_optimized(2000000, 12000, &m, &n, 0);
|
|
get_m_n_optimized(2000000, 13000, &m, &n, 0);
|
|
get_m_n_optimized(2000000, 16800, &m, &n, 800);
|
|
get_m_n_optimized(2000000, 19200, &m, &n, 0);
|
|
get_m_n_optimized(2000000, 26000, &m, &n, 0);
|
|
get_m_n_optimized(2000000, 27000, &m, &n, 0);
|
|
get_m_n_optimized(2000000, 38400, &m, &n, 0);
|
|
|
|
printf("\nMPU - 1200000\n");
|
|
get_m_n_optimized(1200000, 12000, &m, &n, 0);
|
|
get_m_n_optimized(1200000, 13000, &m, &n, 0);
|
|
get_m_n_optimized(1200000, 16800, &m, &n, 800);
|
|
get_m_n_optimized(1200000, 19200, &m, &n, 0);
|
|
get_m_n_optimized(1200000, 26000, &m, &n, 0);
|
|
get_m_n_optimized(1200000, 27000, &m, &n, 0);
|
|
get_m_n_optimized(1200000, 38400, &m, &n, 0);
|
|
|
|
printf("\nMPU - 1584000\n");
|
|
get_m_n_optimized(1584000, 12000, &m, &n, 0);
|
|
get_m_n_optimized(1584000, 13000, &m, &n, 0);
|
|
get_m_n_optimized(1584000, 16800, &m, &n, 400);
|
|
get_m_n_optimized(1584000, 19200, &m, &n, 0);
|
|
get_m_n_optimized(1584000, 26000, &m, &n, 0);
|
|
get_m_n_optimized(1584000, 27000, &m, &n, 0);
|
|
get_m_n_optimized(1584000, 38400, &m, &n, 0);
|
|
|
|
printf("\nCore 1600000\n");
|
|
get_m_n_optimized(1600000, 12000, &m, &n, 0);
|
|
get_m_n_optimized(1600000, 13000, &m, &n, 0);
|
|
get_m_n_optimized(1600000, 16800, &m, &n, 200);
|
|
get_m_n_optimized(1600000, 19200, &m, &n, 0);
|
|
get_m_n_optimized(1600000, 26000, &m, &n, 0);
|
|
get_m_n_optimized(1600000, 27000, &m, &n, 0);
|
|
get_m_n_optimized(1600000, 38400, &m, &n, 0);
|
|
|
|
printf("\nPER 1536000\n");
|
|
get_m_n_optimized(1536000, 12000, &m, &n, 0);
|
|
get_m_n_optimized(1536000, 13000, &m, &n, 0);
|
|
get_m_n_optimized(1536000, 16800, &m, &n, 0);
|
|
get_m_n_optimized(1536000, 19200, &m, &n, 0);
|
|
get_m_n_optimized(1536000, 26000, &m, &n, 0);
|
|
get_m_n_optimized(1536000, 27000, &m, &n, 0);
|
|
get_m_n_optimized(1536000, 38400, &m, &n, 0);
|
|
|
|
printf("\nIVA 1862000\n");
|
|
get_m_n_optimized(1862000, 12000, &m, &n, 0);
|
|
get_m_n_optimized(1862000, 13000, &m, &n, 0);
|
|
get_m_n_optimized(1862000, 16800, &m, &n, 0);
|
|
get_m_n_optimized(1862000, 19200, &m, &n, 900);
|
|
get_m_n_optimized(1862000, 26000, &m, &n, 0);
|
|
get_m_n_optimized(1862000, 27000, &m, &n, 0);
|
|
get_m_n_optimized(1862000, 38400, &m, &n, 800);
|
|
|
|
printf("\nABE 196608 sys clk\n");
|
|
get_m_n_optimized(196608, 12000, &m, &n, 700);
|
|
get_m_n_optimized(196608, 13000, &m, &n, 200);
|
|
get_m_n_optimized(196608, 16800, &m, &n, 700);
|
|
get_m_n_optimized(196608, 19200, &m, &n, 400);
|
|
get_m_n_optimized(196608, 26000, &m, &n, 200);
|
|
get_m_n_optimized(196608, 27000, &m, &n, 900);
|
|
get_m_n_optimized(196608, 38400, &m, &n, 0);
|
|
|
|
printf("\nABE 196608 32K\n");
|
|
get_m_n_optimized(196608000/4, 32768, &m, &n, 0);
|
|
|
|
printf("\nUSB 1920000\n");
|
|
get_m_n_optimized(1920000, 12000, &m, &n, 0);
|
|
get_m_n_optimized(1920000, 13000, &m, &n, 0);
|
|
get_m_n_optimized(1920000, 16800, &m, &n, 0);
|
|
get_m_n_optimized(1920000, 19200, &m, &n, 0);
|
|
get_m_n_optimized(1920000, 26000, &m, &n, 0);
|
|
get_m_n_optimized(1920000, 27000, &m, &n, 0);
|
|
get_m_n_optimized(1920000, 38400, &m, &n, 0);
|
|
|
|
printf("\nCore ES1 1523712\n");
|
|
get_m_n_optimized(1524000, 12000, &m, &n, 100);
|
|
get_m_n_optimized(1524000, 13000, &m, &n, 0);
|
|
get_m_n_optimized(1524000, 16800, &m, &n, 0);
|
|
get_m_n_optimized(1524000, 19200, &m, &n, 0);
|
|
get_m_n_optimized(1524000, 26000, &m, &n, 0);
|
|
get_m_n_optimized(1524000, 27000, &m, &n, 0);
|
|
|
|
/* exact recommendation for SDPs */
|
|
get_m_n_optimized(1523712, 38400, &m, &n, 0);
|
|
|
|
}
|