MicroAPRS/bertos/cpu/arm/hw/pll_at91.h

154 lines
4.9 KiB
C

/**
* \file
* <!--
* This file is part of BeRTOS.
*
* Bertos 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
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* GNU General Public License for more details.
*
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* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* As a special exception, you may use this file as part of a free software
* library without restriction. Specifically, if other files instantiate
* templates or use macros or inline functions from this file, or you compile
* this file and link it with other files to produce an executable, this
* file does not by itself cause the resulting executable to be covered by
* the GNU General Public License. This exception does not however
* invalidate any other reasons why the executable file might be covered by
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* Copyright 2010 Develer S.r.l. (http://www.develer.com/)
*
* -->
*
*
* \author Giovanni Bajo <rasky@develer.com>
*
* \brief AT91SAM7S256 CRT.
*/
#include <io/arm.h>
#include <cfg/macros.h>
#if 1
// Versione completamente unrollata
#define CREATE_PLL_STEP(xtal, cpufreq)
#define PLL_STEP(xtal, cpufreq, d, k) \
do { \
uint32_t m = (((cpufreq * (1LL << k) * (d)) + (xtal / 2)) / xtal) - 1; \
if (m < 2048) \
{ \
uint32_t pll = (d != 0) ? (xtal * (m + 1)) / (d) : 0; \
if (80000000 <= pll && pll <= 160000000) \
{ \
uint32_t err = ABS((int32_t)((pll >> k) - cpufreq)); \
if (err < best_err) \
{ \
best_err=err; best_m=m; best_k=k; best_d=d; \
} \
} \
} \
} while (0)
#else
// Versione con funzione nestata (GCC only)
// Tempo di compilazione più rapido
#define CREATE_PLL_STEP(xtal, cpufreq) \
void __attribute__((always_inline)) PLL_STEP(int u1, int u2, int32_t d, long long k) \
{ \
(void)u1; (void)u2; \
uint32_t m = ((((cpufreq * (1LL << k) * (d)) + (xtal / 2)) / xtal) - 1; \
if (m < 2048) \
{ \
uint32_t pll = (xtal * (m + 1)) / (d); \
if (80000000UL <= pll && pll <= 160000000UL) \
{ \
uint32_t err = ABS((int32_t)((pll >> k) - cpufreq)); \
if (err < best_err) \
{ \
best_err=err; best_m=m; best_k=k; best_d=d; \
} \
} \
} \
}
#endif
#define PLL_MACRO_STEP(xtal, cpufreq, d) \
do { \
if ((d) > 0 && (d) <= 255 && \
(d) <= xtal / 1000000 && (d) >= xtal / 32000000) \
{ \
PLL_STEP(xtal, cpufreq, d, 0); \
PLL_STEP(xtal, cpufreq, d, 1); \
PLL_STEP(xtal, cpufreq, d, 2); \
PLL_STEP(xtal, cpufreq, d, 3); \
PLL_STEP(xtal, cpufreq, d, 4); \
PLL_STEP(xtal, cpufreq, d, 5); \
PLL_STEP(xtal, cpufreq, d, 6); \
} \
} while (0)
#define PLL_ITERATION_4(xtal, cpufreq, d) \
PLL_MACRO_STEP(xtal, cpufreq, d)
#define PLL_ITERATION_3(xtal, cpufreq, d) \
PLL_ITERATION_4(xtal, cpufreq, (d)*4+0); \
PLL_ITERATION_4(xtal, cpufreq, (d)*4+1); \
PLL_ITERATION_4(xtal, cpufreq, (d)*4+2); \
PLL_ITERATION_4(xtal, cpufreq, (d)*4+3);
#define PLL_ITERATION_2(xtal, cpufreq, d) \
PLL_ITERATION_3(xtal, cpufreq, (d)*4+0); \
PLL_ITERATION_3(xtal, cpufreq, (d)*4+1); \
PLL_ITERATION_3(xtal, cpufreq, (d)*4+2); \
PLL_ITERATION_3(xtal, cpufreq, (d)*4+3);
#define PLL_ITERATION_1(xtal, cpufreq, d) \
PLL_ITERATION_2(xtal, cpufreq, (d)*4+0); \
PLL_ITERATION_2(xtal, cpufreq, (d)*4+1); \
PLL_ITERATION_2(xtal, cpufreq, (d)*4+2); \
PLL_ITERATION_2(xtal, cpufreq, (d)*4+3);
#define PLL_ITERATION(xtal, cpufreq) \
PLL_ITERATION_1(xtal, cpufreq, 0); \
PLL_ITERATION_1(xtal, cpufreq, 1); \
PLL_ITERATION_1(xtal, cpufreq, 2); \
PLL_ITERATION_1(xtal, cpufreq, 3)
#define PLL_CALC(xtal, cpufreq, m, d, k) do \
{ \
uint32_t best_err=cpufreq, best_m, best_k, best_d; \
CREATE_PLL_STEP(xtal, cpufreq) \
PLL_ITERATION(xtal, cpufreq); \
*(m)=best_m; *(d)=best_d; *(k)=best_k; \
} while (0)
#if 0
int main(int argc, char *argv[])
{
int32_t m, d, k;
PLL_CALC(18432000, 48054857, &m, &d, &k);
if (__builtin_constant_p(m) && __builtin_constant_p(k) && __builtin_constant_p(d))
printf("SUCCESS -- compile time evaluation\n");
else
printf("FAILURE -- run time evaluation\n");
printf("M:%d D:%d K:%d\n", m, d, k);
}
#endif