diff options
Diffstat (limited to 'tools/omap')
| -rw-r--r-- | tools/omap/clocks_get_m_n.c | 197 |
1 files changed, 197 insertions, 0 deletions
diff --git a/tools/omap/clocks_get_m_n.c b/tools/omap/clocks_get_m_n.c new file mode 100644 index 0000000..cfc1760 --- /dev/null +++ b/tools/omap/clocks_get_m_n.c @@ -0,0 +1,197 @@ +/* + * 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); + +} |