pll_at91.h

Go to the documentation of this file.
00001 
00039 #include <io/arm.h>
00040 #include <cfg/macros.h>
00041 
00042 #if 1
00043 // Versione completamente unrollata
00044 
00045 #define CREATE_PLL_STEP(xtal, cpufreq)
00046 
00047 #define PLL_STEP(xtal, cpufreq, d, k) \
00048     do { \
00049         uint32_t m = (((cpufreq * (1LL << k) * (d))  + (xtal / 2)) / xtal) - 1; \
00050         if (m < 2048) \
00051         { \
00052             uint32_t pll = (d != 0) ? (xtal * (m + 1)) / (d) : 0; \
00053             if (80000000 <= pll && pll <= 160000000) \
00054             { \
00055         uint32_t err = ABS((int32_t)((pll >> k) - cpufreq)); \
00056                 if (err < best_err) \
00057                 { \
00058                     best_err=err; best_m=m; best_k=k; best_d=d; \
00059                 } \
00060             } \
00061         } \
00062     } while (0)
00063 
00064 #else
00065 
00066 // Versione con funzione nestata (GCC only)
00067 // Tempo di compilazione più rapido
00068 
00069 #define CREATE_PLL_STEP(xtal, cpufreq) \
00070     void __attribute__((always_inline)) PLL_STEP(int u1, int u2, int32_t d, long long k)  \
00071     { \
00072         (void)u1; (void)u2; \
00073         uint32_t m = ((((cpufreq * (1LL << k) * (d))  + (xtal / 2)) / xtal) - 1; \
00074         if (m < 2048) \
00075         { \
00076             uint32_t pll = (xtal * (m + 1)) / (d); \
00077             if (80000000UL <= pll && pll <= 160000000UL) \
00078             { \
00079                 uint32_t err = ABS((int32_t)((pll >> k) - cpufreq)); \
00080                 if (err < best_err) \
00081                 { \
00082                     best_err=err; best_m=m; best_k=k; best_d=d; \
00083                 } \
00084             } \
00085         } \
00086     }
00087 
00088 #endif
00089 
00090 #define PLL_MACRO_STEP(xtal, cpufreq, d) \
00091     do { \
00092         if ((d) > 0 && (d) <= 255 && \
00093             (d) <= xtal / 1000000 && (d) >= xtal / 32000000) \
00094         { \
00095             PLL_STEP(xtal, cpufreq, d, 0); \
00096             PLL_STEP(xtal, cpufreq, d, 1); \
00097             PLL_STEP(xtal, cpufreq, d, 2); \
00098             PLL_STEP(xtal, cpufreq, d, 3); \
00099             PLL_STEP(xtal, cpufreq, d, 4); \
00100             PLL_STEP(xtal, cpufreq, d, 5); \
00101             PLL_STEP(xtal, cpufreq, d, 6); \
00102         } \
00103     } while (0)
00104 
00105 #define PLL_ITERATION_4(xtal, cpufreq, d) \
00106     PLL_MACRO_STEP(xtal, cpufreq, d)
00107 
00108 #define PLL_ITERATION_3(xtal, cpufreq, d) \
00109     PLL_ITERATION_4(xtal, cpufreq, (d)*4+0); \
00110     PLL_ITERATION_4(xtal, cpufreq, (d)*4+1); \
00111     PLL_ITERATION_4(xtal, cpufreq, (d)*4+2); \
00112     PLL_ITERATION_4(xtal, cpufreq, (d)*4+3);
00113 
00114 #define PLL_ITERATION_2(xtal, cpufreq, d) \
00115     PLL_ITERATION_3(xtal, cpufreq, (d)*4+0); \
00116     PLL_ITERATION_3(xtal, cpufreq, (d)*4+1); \
00117     PLL_ITERATION_3(xtal, cpufreq, (d)*4+2); \
00118     PLL_ITERATION_3(xtal, cpufreq, (d)*4+3);
00119 
00120 #define PLL_ITERATION_1(xtal, cpufreq, d) \
00121     PLL_ITERATION_2(xtal, cpufreq, (d)*4+0); \
00122     PLL_ITERATION_2(xtal, cpufreq, (d)*4+1); \
00123     PLL_ITERATION_2(xtal, cpufreq, (d)*4+2); \
00124     PLL_ITERATION_2(xtal, cpufreq, (d)*4+3);
00125 
00126 #define PLL_ITERATION(xtal, cpufreq) \
00127     PLL_ITERATION_1(xtal, cpufreq, 0); \
00128     PLL_ITERATION_1(xtal, cpufreq, 1); \
00129     PLL_ITERATION_1(xtal, cpufreq, 2); \
00130     PLL_ITERATION_1(xtal, cpufreq, 3)
00131 
00132 #define PLL_CALC(xtal, cpufreq, m, d, k) do \
00133     { \
00134         uint32_t best_err=cpufreq, best_m, best_k, best_d; \
00135         CREATE_PLL_STEP(xtal, cpufreq) \
00136         PLL_ITERATION(xtal, cpufreq); \
00137         *(m)=best_m; *(d)=best_d; *(k)=best_k; \
00138     } while (0)
00139 
00140 #if 0
00141 int main(int argc, char *argv[])
00142 {
00143     int32_t m, d, k;
00144     PLL_CALC(18420000, 48023000, &m, &d, &k);
00145 
00146     if (__builtin_constant_p(m) && __builtin_constant_p(k) && __builtin_constant_p(d))
00147         printf("SUCCESS -- compile time evaluation\n");
00148     else
00149         printf("FAILURE -- run time evaluation\n");
00150 
00151     printf("M:%d D:%d K:%d\n", m, d, k);
00152 }
00153 #endif