4 * \brief Provides the low-level initialization functions that called
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7 * Copyright (c) 2011 - 2012 Atmel Corporation. All rights reserved.
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13 * Redistribution and use in source and binary forms, with or without
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14 * modification, are permitted provided that the following conditions are met:
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16 * 1. Redistributions of source code must retain the above copyright notice,
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17 * this list of conditions and the following disclaimer.
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19 * 2. Redistributions in binary form must reproduce the above copyright notice,
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20 * this list of conditions and the following disclaimer in the documentation
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21 * and/or other materials provided with the distribution.
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23 * 3. The name of Atmel may not be used to endorse or promote products derived
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24 * from this software without specific prior written permission.
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26 * 4. This software may only be redistributed and used in connection with an
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27 * Atmel microcontroller product.
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29 * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
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30 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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31 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
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32 * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
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33 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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34 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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35 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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36 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
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37 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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38 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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39 * POSSIBILITY OF SUCH DAMAGE.
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45 #include "system_sam3x.h"
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56 /* Clock settings (84MHz) */
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57 #define SYS_BOARD_OSCOUNT (CKGR_MOR_MOSCXTST(0x8))
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58 #define SYS_BOARD_PLLAR (CKGR_PLLAR_ONE \
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59 | CKGR_PLLAR_MULA(0xdUL) \
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60 | CKGR_PLLAR_PLLACOUNT(0x3fUL) \
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61 | CKGR_PLLAR_DIVA(0x1UL))
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62 #define SYS_BOARD_MCKR (PMC_MCKR_PRES_CLK_2 | PMC_MCKR_CSS_PLLA_CLK)
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64 /* Clock Definitions */
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65 #define SYS_UTMIPLL (480000000UL) /* UTMI PLL frequency */
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67 #define SYS_CKGR_MOR_KEY_VALUE CKGR_MOR_KEY(0x37) /* Key to unlock MOR register */
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69 /* FIXME: should be generated by sock */
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70 uint32_t SystemCoreClock = CHIP_FREQ_MAINCK_RC_4MHZ;
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73 * \brief Setup the microcontroller system.
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74 * Initialize the System and update the SystemFrequency variable.
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76 void SystemInit(void)
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78 /* Set FWS according to SYS_BOARD_MCKR configuration */
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79 EFC0->EEFC_FMR = EEFC_FMR_FWS(4);
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80 EFC1->EEFC_FMR = EEFC_FMR_FWS(4);
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82 /* Initialize main oscillator */
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83 if (!(PMC->CKGR_MOR & CKGR_MOR_MOSCSEL)) {
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84 PMC->CKGR_MOR = SYS_CKGR_MOR_KEY_VALUE | SYS_BOARD_OSCOUNT |
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85 CKGR_MOR_MOSCRCEN | CKGR_MOR_MOSCXTEN;
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86 while (!(PMC->PMC_SR & PMC_SR_MOSCXTS)) {
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90 /* Switch to 3-20MHz Xtal oscillator */
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91 PMC->CKGR_MOR = SYS_CKGR_MOR_KEY_VALUE | SYS_BOARD_OSCOUNT |
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92 CKGR_MOR_MOSCRCEN | CKGR_MOR_MOSCXTEN | CKGR_MOR_MOSCSEL;
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94 while (!(PMC->PMC_SR & PMC_SR_MOSCSELS)) {
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96 PMC->PMC_MCKR = (PMC->PMC_MCKR & ~(uint32_t)PMC_MCKR_CSS_Msk) |
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97 PMC_MCKR_CSS_MAIN_CLK;
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98 while (!(PMC->PMC_SR & PMC_SR_MCKRDY)) {
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101 /* Initialize PLLA */
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102 PMC->CKGR_PLLAR = SYS_BOARD_PLLAR;
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103 while (!(PMC->PMC_SR & PMC_SR_LOCKA)) {
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106 /* Switch to main clock */
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107 PMC->PMC_MCKR = (SYS_BOARD_MCKR & ~PMC_MCKR_CSS_Msk) | PMC_MCKR_CSS_MAIN_CLK;
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108 while (!(PMC->PMC_SR & PMC_SR_MCKRDY)) {
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111 /* Switch to PLLA */
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112 PMC->PMC_MCKR = SYS_BOARD_MCKR;
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113 while (!(PMC->PMC_SR & PMC_SR_MCKRDY)) {
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116 SystemCoreClock = CHIP_FREQ_CPU_MAX;
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119 void SystemCoreClockUpdate(void)
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121 /* Determine clock frequency according to clock register values */
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122 switch (PMC->PMC_MCKR & PMC_MCKR_CSS_Msk) {
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123 case PMC_MCKR_CSS_SLOW_CLK: /* Slow clock */
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124 if (SUPC->SUPC_SR & SUPC_SR_OSCSEL) {
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125 SystemCoreClock = CHIP_FREQ_XTAL_32K;
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127 SystemCoreClock = CHIP_FREQ_SLCK_RC;
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130 case PMC_MCKR_CSS_MAIN_CLK: /* Main clock */
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131 if (PMC->CKGR_MOR & CKGR_MOR_MOSCSEL) {
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132 SystemCoreClock = CHIP_FREQ_XTAL_12M;
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134 SystemCoreClock = CHIP_FREQ_MAINCK_RC_4MHZ;
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136 switch (PMC->CKGR_MOR & CKGR_MOR_MOSCRCF_Msk) {
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137 case CKGR_MOR_MOSCRCF_4_MHz:
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139 case CKGR_MOR_MOSCRCF_8_MHz:
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140 SystemCoreClock *= 2U;
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142 case CKGR_MOR_MOSCRCF_12_MHz:
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143 SystemCoreClock *= 3U;
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150 case PMC_MCKR_CSS_PLLA_CLK: /* PLLA clock */
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151 case PMC_MCKR_CSS_UPLL_CLK: /* UPLL clock */
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152 if (PMC->CKGR_MOR & CKGR_MOR_MOSCSEL) {
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153 SystemCoreClock = CHIP_FREQ_XTAL_12M;
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155 SystemCoreClock = CHIP_FREQ_MAINCK_RC_4MHZ;
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157 switch (PMC->CKGR_MOR & CKGR_MOR_MOSCRCF_Msk) {
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158 case CKGR_MOR_MOSCRCF_4_MHz:
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160 case CKGR_MOR_MOSCRCF_8_MHz:
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161 SystemCoreClock *= 2U;
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163 case CKGR_MOR_MOSCRCF_12_MHz:
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164 SystemCoreClock *= 3U;
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170 if ((PMC->PMC_MCKR & PMC_MCKR_CSS_Msk) == PMC_MCKR_CSS_PLLA_CLK) {
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171 SystemCoreClock *= ((((PMC->CKGR_PLLAR) & CKGR_PLLAR_MULA_Msk) >>
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172 CKGR_PLLAR_MULA_Pos) + 1U);
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173 SystemCoreClock /= ((((PMC->CKGR_PLLAR) & CKGR_PLLAR_DIVA_Msk) >>
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174 CKGR_PLLAR_DIVA_Pos));
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176 SystemCoreClock = SYS_UTMIPLL / 2U;
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181 if ((PMC->PMC_MCKR & PMC_MCKR_PRES_Msk) == PMC_MCKR_PRES_CLK_3) {
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182 SystemCoreClock /= 3U;
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184 SystemCoreClock >>= ((PMC->PMC_MCKR & PMC_MCKR_PRES_Msk) >>
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185 PMC_MCKR_PRES_Pos);
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190 * Initialize flash.
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192 void system_init_flash(uint32_t ul_clk)
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194 /* Set FWS for embedded Flash access according to operating frequency */
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195 if (ul_clk < CHIP_FREQ_FWS_0) {
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196 EFC0->EEFC_FMR = EEFC_FMR_FWS(0);
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197 EFC1->EEFC_FMR = EEFC_FMR_FWS(0);
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198 } else if (ul_clk < CHIP_FREQ_FWS_1) {
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199 EFC0->EEFC_FMR = EEFC_FMR_FWS(1);
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200 EFC1->EEFC_FMR = EEFC_FMR_FWS(1);
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201 } else if (ul_clk < CHIP_FREQ_FWS_2) {
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202 EFC0->EEFC_FMR = EEFC_FMR_FWS(2);
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203 EFC1->EEFC_FMR = EEFC_FMR_FWS(2);
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204 } else if (ul_clk < CHIP_FREQ_FWS_3) {
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205 EFC0->EEFC_FMR = EEFC_FMR_FWS(3);
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206 EFC1->EEFC_FMR = EEFC_FMR_FWS(3);
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208 EFC0->EEFC_FMR = EEFC_FMR_FWS(4);
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209 EFC1->EEFC_FMR = EEFC_FMR_FWS(4);
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