/** * \file * * \brief Provides the low-level initialization functions that called * on chip startup. * * Copyright (c) 2014-2015 Atmel Corporation. All rights reserved. * * \asf_license_start * * \page License * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * 1. Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright notice, * this list of conditions and the following disclaimer in the documentation * and/or other materials provided with the distribution. * * 3. The name of Atmel may not be used to endorse or promote products derived * from this software without specific prior written permission. * * 4. This software may only be redistributed and used in connection with an * Atmel microcontroller product. * * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * * \asf_license_stop * */ /* * Support and FAQ: visit <a href="http://www.atmel.com/design-support/">Atmel Support</a> */ #include "system_samg55.h" #include "samg55.h" /* @cond 0 */ /**INDENT-OFF**/ #ifdef __cplusplus extern "C" { #endif /**INDENT-ON**/ /* @endcond */ /* Clock Settings (120MHz) */ #define SYS_BOARD_PLLAR (CKGR_PLLAR_MULA(0xe4eU) \ | CKGR_PLLAR_PLLACOUNT(0x3fU) \ | CKGR_PLLAR_PLLAEN(0x1U)) #define SYS_BOARD_MCKR (PMC_MCKR_PRES_CLK_1 | PMC_MCKR_CSS_PLLA_CLK) /* Key to unlock MOR register */ #define SYS_CKGR_MOR_KEY_VALUE CKGR_MOR_KEY(0x37) /* External oscillator definition, to be overriden by application */ #define CHIP_FREQ_XTAL_12M (12000000UL) #if (!defined CHIP_FREQ_XTAL) # define CHIP_FREQ_XTAL CHIP_FREQ_XTAL_12M #endif uint32_t SystemCoreClock = CHIP_FREQ_MAINCK_RC_8MHZ; /** * \brief Setup the microcontroller system. * Initialize the System and update the SystemFrequency variable. */ void SystemInit(void) { /* Set FWS according to SYS_BOARD_MCKR configuration */ EFC->EEFC_FMR = EEFC_FMR_FWS(8)|EEFC_FMR_CLOE; /* Initialize PLLA */ PMC->CKGR_PLLAR = SYS_BOARD_PLLAR; while (!(PMC->PMC_SR & PMC_SR_LOCKA)) { } /* Switch to PLLA */ PMC->PMC_MCKR = SYS_BOARD_MCKR; while (!(PMC->PMC_SR & PMC_SR_MCKRDY)) { } SystemCoreClock = CHIP_FREQ_CPU_MAX; } void SystemCoreClockUpdate(void) { /* Determine clock frequency according to clock register values */ switch (PMC->PMC_MCKR & (uint32_t) PMC_MCKR_CSS_Msk) { case PMC_MCKR_CSS_SLOW_CLK: /* Slow clock */ if (SUPC->SUPC_SR & SUPC_SR_OSCSEL) { SystemCoreClock = CHIP_FREQ_XTAL_32K; } else { SystemCoreClock = CHIP_FREQ_SLCK_RC; } break; case PMC_MCKR_CSS_MAIN_CLK: /* Main clock */ if (PMC->CKGR_MOR & CKGR_MOR_MOSCSEL) { SystemCoreClock = CHIP_FREQ_XTAL; } else { SystemCoreClock = CHIP_FREQ_MAINCK_RC_8MHZ; switch (PMC->CKGR_MOR & CKGR_MOR_MOSCRCF_Msk) { case CKGR_MOR_MOSCRCF_8_MHz: break; case CKGR_MOR_MOSCRCF_16_MHz: SystemCoreClock *= 2U; break; case CKGR_MOR_MOSCRCF_24_MHz: SystemCoreClock *= 3U; break; default: break; } } break; case PMC_MCKR_CSS_PLLA_CLK: /* PLLA clock */ if (SUPC->SUPC_SR & SUPC_SR_OSCSEL) { SystemCoreClock = CHIP_FREQ_XTAL_32K; } else { SystemCoreClock = CHIP_FREQ_SLCK_RC; } if ((uint32_t) (PMC->PMC_MCKR & (uint32_t) PMC_MCKR_CSS_Msk) == PMC_MCKR_CSS_PLLA_CLK) { SystemCoreClock *= ((((PMC->CKGR_PLLAR) & CKGR_PLLAR_MULA_Msk) >> CKGR_PLLAR_MULA_Pos) + 1U); } break; default: break; } if ((PMC->PMC_MCKR & PMC_MCKR_PRES_Msk) == PMC_MCKR_PRES_CLK_3) { SystemCoreClock /= 3U; } else { SystemCoreClock >>= ((PMC->PMC_MCKR & PMC_MCKR_PRES_Msk) >> PMC_MCKR_PRES_Pos); } } /** * Initialize flash. */ void system_init_flash(uint32_t ul_clk) { /* Set FWS for embedded Flash access according to operating frequency */ if (ul_clk < CHIP_FREQ_FWS_0) { EFC->EEFC_FMR = EEFC_FMR_FWS(0)|EEFC_FMR_CLOE; } else if (ul_clk < CHIP_FREQ_FWS_1) { EFC->EEFC_FMR = EEFC_FMR_FWS(1)|EEFC_FMR_CLOE; } else if (ul_clk < CHIP_FREQ_FWS_2) { EFC->EEFC_FMR = EEFC_FMR_FWS(2)|EEFC_FMR_CLOE; } else if (ul_clk < CHIP_FREQ_FWS_3) { EFC->EEFC_FMR = EEFC_FMR_FWS(3)|EEFC_FMR_CLOE; } else if (ul_clk < CHIP_FREQ_FWS_4) { EFC->EEFC_FMR = EEFC_FMR_FWS(4)|EEFC_FMR_CLOE; } else { EFC->EEFC_FMR = EEFC_FMR_FWS(5)|EEFC_FMR_CLOE; } } /* @cond 0 */ /**INDENT-OFF**/ #ifdef __cplusplus } #endif /**INDENT-ON**/ /* @endcond */