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Commit | Line | Data |
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3776801d A |
1 | /* |
2 | * Program for finding M & N values for DPLLs | |
3 | * To be run on Host PC | |
4 | * | |
5 | * (C) Copyright 2010 | |
6 | * Texas Instruments, <www.ti.com> | |
7 | * | |
8 | * Aneesh V <[email protected]> | |
9 | * | |
1a459660 | 10 | * SPDX-License-Identifier: GPL-2.0+ |
3776801d A |
11 | */ |
12 | #include <stdlib.h> | |
13 | #include <stdio.h> | |
14 | typedef unsigned int u32; | |
15 | #define MAX_N 127 | |
16 | ||
17 | /* | |
18 | * get_m_n_optimized() - Finds optimal DPLL multiplier(M) and divider(N) | |
19 | * values based on the reference frequency, required output frequency, | |
20 | * maximum tolerance for output frequency etc. | |
21 | * | |
22 | * target_freq_khz - output frequency required in KHz | |
23 | * ref_freq_khz - reference(input) frequency in KHz | |
24 | * m - pointer to computed M value | |
25 | * n - pointer to computed N value | |
26 | * tolerance_khz - tolerance for the output frequency. When the algorithm | |
27 | * succeeds in finding vialble M and N values the corresponding output | |
28 | * frequency will be in the range: | |
29 | * [target_freq_khz - tolerance_khz, target_freq_khz] | |
30 | * | |
31 | * Formula: | |
32 | * Fdpll = (2 * M * Fref) / (N + 1) | |
33 | * | |
34 | * Considerations for lock-time: | |
35 | * - Smaller the N, better lock-time, especially lock-time will be | |
36 | * - For acceptable lock-times: | |
37 | * Fref / (M + 1) >= 1 MHz | |
38 | * | |
39 | * Considerations for power: | |
40 | * - The difference in power for different N values giving the same | |
41 | * output is negligible. So, we optimize for lock-time | |
42 | * | |
43 | * Hard-constraints: | |
44 | * - N can not be greater than 127(7 bit field for representing N) | |
45 | * | |
46 | * Usage: | |
47 | * $ gcc clocks_get_m_n.c | |
48 | * $ ./a.out | |
49 | */ | |
28a181ff | 50 | int get_m_n_optimized(u32 target_freq_khz, u32 ref_freq_khz, u32 *M, u32 *N) |
3776801d | 51 | { |
28a181ff A |
52 | u32 freq = target_freq_khz; |
53 | u32 m_optimal, n_optimal, freq_optimal = 0, freq_old; | |
54 | u32 m, n; | |
55 | n = 1; | |
3776801d | 56 | while (1) { |
28a181ff | 57 | m = target_freq_khz / ref_freq_khz / 2 * n; |
3776801d A |
58 | freq_old = 0; |
59 | while (1) { | |
28a181ff A |
60 | freq = ref_freq_khz * 2 * m / n; |
61 | if (freq > target_freq_khz) { | |
3776801d | 62 | freq = freq_old; |
28a181ff | 63 | m--; |
3776801d A |
64 | break; |
65 | } | |
28a181ff | 66 | m++; |
3776801d A |
67 | freq_old = freq; |
68 | } | |
28a181ff A |
69 | if (freq > freq_optimal) { |
70 | freq_optimal = freq; | |
71 | m_optimal = m; | |
72 | n_optimal = n; | |
73 | } | |
74 | n++; | |
75 | if ((freq_optimal == target_freq_khz) || | |
76 | ((ref_freq_khz / n) < 1000)) { | |
3776801d | 77 | break; |
3776801d A |
78 | } |
79 | } | |
28a181ff A |
80 | n--; |
81 | *M = m_optimal; | |
82 | *N = n_optimal - 1; | |
83 | printf("ref %d m %d n %d target %d locked %d\n", ref_freq_khz, | |
84 | m_optimal, n_optimal - 1, target_freq_khz, freq_optimal); | |
3776801d A |
85 | return 0; |
86 | } | |
87 | ||
88 | void main(void) | |
89 | { | |
90 | u32 m, n; | |
91 | printf("\nMPU - 2000000\n"); | |
28a181ff A |
92 | get_m_n_optimized(2000000, 12000, &m, &n); |
93 | get_m_n_optimized(2000000, 13000, &m, &n); | |
94 | get_m_n_optimized(2000000, 16800, &m, &n); | |
95 | get_m_n_optimized(2000000, 19200, &m, &n); | |
96 | get_m_n_optimized(2000000, 26000, &m, &n); | |
97 | get_m_n_optimized(2000000, 27000, &m, &n); | |
98 | get_m_n_optimized(2000000, 38400, &m, &n); | |
3776801d A |
99 | |
100 | printf("\nMPU - 1200000\n"); | |
28a181ff A |
101 | get_m_n_optimized(1200000, 12000, &m, &n); |
102 | get_m_n_optimized(1200000, 13000, &m, &n); | |
103 | get_m_n_optimized(1200000, 16800, &m, &n); | |
104 | get_m_n_optimized(1200000, 19200, &m, &n); | |
105 | get_m_n_optimized(1200000, 26000, &m, &n); | |
106 | get_m_n_optimized(1200000, 27000, &m, &n); | |
107 | get_m_n_optimized(1200000, 38400, &m, &n); | |
3776801d A |
108 | |
109 | printf("\nMPU - 1584000\n"); | |
28a181ff A |
110 | get_m_n_optimized(1584000, 12000, &m, &n); |
111 | get_m_n_optimized(1584000, 13000, &m, &n); | |
112 | get_m_n_optimized(1584000, 16800, &m, &n); | |
113 | get_m_n_optimized(1584000, 19200, &m, &n); | |
114 | get_m_n_optimized(1584000, 26000, &m, &n); | |
115 | get_m_n_optimized(1584000, 27000, &m, &n); | |
116 | get_m_n_optimized(1584000, 38400, &m, &n); | |
3776801d A |
117 | |
118 | printf("\nCore 1600000\n"); | |
28a181ff A |
119 | get_m_n_optimized(1600000, 12000, &m, &n); |
120 | get_m_n_optimized(1600000, 13000, &m, &n); | |
121 | get_m_n_optimized(1600000, 16800, &m, &n); | |
122 | get_m_n_optimized(1600000, 19200, &m, &n); | |
123 | get_m_n_optimized(1600000, 26000, &m, &n); | |
124 | get_m_n_optimized(1600000, 27000, &m, &n); | |
125 | get_m_n_optimized(1600000, 38400, &m, &n); | |
3776801d A |
126 | |
127 | printf("\nPER 1536000\n"); | |
28a181ff A |
128 | get_m_n_optimized(1536000, 12000, &m, &n); |
129 | get_m_n_optimized(1536000, 13000, &m, &n); | |
130 | get_m_n_optimized(1536000, 16800, &m, &n); | |
131 | get_m_n_optimized(1536000, 19200, &m, &n); | |
132 | get_m_n_optimized(1536000, 26000, &m, &n); | |
133 | get_m_n_optimized(1536000, 27000, &m, &n); | |
134 | get_m_n_optimized(1536000, 38400, &m, &n); | |
3776801d A |
135 | |
136 | printf("\nIVA 1862000\n"); | |
28a181ff A |
137 | get_m_n_optimized(1862000, 12000, &m, &n); |
138 | get_m_n_optimized(1862000, 13000, &m, &n); | |
139 | get_m_n_optimized(1862000, 16800, &m, &n); | |
140 | get_m_n_optimized(1862000, 19200, &m, &n); | |
141 | get_m_n_optimized(1862000, 26000, &m, &n); | |
142 | get_m_n_optimized(1862000, 27000, &m, &n); | |
143 | get_m_n_optimized(1862000, 38400, &m, &n); | |
144 | ||
145 | printf("\nIVA Nitro - 1290000\n"); | |
146 | get_m_n_optimized(1290000, 12000, &m, &n); | |
147 | get_m_n_optimized(1290000, 13000, &m, &n); | |
148 | get_m_n_optimized(1290000, 16800, &m, &n); | |
149 | get_m_n_optimized(1290000, 19200, &m, &n); | |
150 | get_m_n_optimized(1290000, 26000, &m, &n); | |
151 | get_m_n_optimized(1290000, 27000, &m, &n); | |
152 | get_m_n_optimized(1290000, 38400, &m, &n); | |
3776801d A |
153 | |
154 | printf("\nABE 196608 sys clk\n"); | |
28a181ff A |
155 | get_m_n_optimized(196608, 12000, &m, &n); |
156 | get_m_n_optimized(196608, 13000, &m, &n); | |
157 | get_m_n_optimized(196608, 16800, &m, &n); | |
158 | get_m_n_optimized(196608, 19200, &m, &n); | |
159 | get_m_n_optimized(196608, 26000, &m, &n); | |
160 | get_m_n_optimized(196608, 27000, &m, &n); | |
161 | get_m_n_optimized(196608, 38400, &m, &n); | |
3776801d A |
162 | |
163 | printf("\nABE 196608 32K\n"); | |
28a181ff | 164 | get_m_n_optimized(196608000/4, 32768, &m, &n); |
3776801d A |
165 | |
166 | printf("\nUSB 1920000\n"); | |
28a181ff A |
167 | get_m_n_optimized(1920000, 12000, &m, &n); |
168 | get_m_n_optimized(1920000, 13000, &m, &n); | |
169 | get_m_n_optimized(1920000, 16800, &m, &n); | |
170 | get_m_n_optimized(1920000, 19200, &m, &n); | |
171 | get_m_n_optimized(1920000, 26000, &m, &n); | |
172 | get_m_n_optimized(1920000, 27000, &m, &n); | |
173 | get_m_n_optimized(1920000, 38400, &m, &n); | |
3776801d A |
174 | |
175 | printf("\nCore ES1 1523712\n"); | |
28a181ff A |
176 | get_m_n_optimized(1524000, 12000, &m, &n); |
177 | get_m_n_optimized(1524000, 13000, &m, &n); | |
178 | get_m_n_optimized(1524000, 16800, &m, &n); | |
179 | get_m_n_optimized(1524000, 19200, &m, &n); | |
180 | get_m_n_optimized(1524000, 26000, &m, &n); | |
181 | get_m_n_optimized(1524000, 27000, &m, &n); | |
3776801d A |
182 | |
183 | /* exact recommendation for SDPs */ | |
28a181ff | 184 | get_m_n_optimized(1523712, 38400, &m, &n); |
3776801d A |
185 | |
186 | } |