/**************************************************************************//** * @file system_ARMCM4.c * @brief CMSIS Device System Source File for * ARMCM4 Device * @version V5.3.1 * @date 09. July 2018 ******************************************************************************/ /* * Copyright (c) 2009-2018 Arm Limited. All rights reserved. * * SPDX-License-Identifier: Apache-2.0 * * Licensed under the Apache License, Version 2.0 (the License); you may * not use this file except in compliance with the License. * You may obtain a copy of the License at * * www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an AS IS BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #if defined (ARMCM4) #include "ARMCM4.h" #elif defined (ARMCM4_FP) #include "ARMCM4_FP.h" #else #error device not specified! #endif /*---------------------------------------------------------------------------- Define clocks *----------------------------------------------------------------------------*/ #define XTAL (50000000UL) /* Oscillator frequency */ #define SYSTEM_CLOCK (XTAL / 2U) /*---------------------------------------------------------------------------- Externals *----------------------------------------------------------------------------*/ #if defined (__VTOR_PRESENT) && (__VTOR_PRESENT == 1U) extern uint32_t __Vectors; #endif /*---------------------------------------------------------------------------- System Core Clock Variable *----------------------------------------------------------------------------*/ uint32_t SystemCoreClock = SYSTEM_CLOCK; /* System Core Clock Frequency */ /*---------------------------------------------------------------------------- System Core Clock update function *----------------------------------------------------------------------------*/ void SystemCoreClockUpdate (void) { SystemCoreClock = SYSTEM_CLOCK; } /*---------------------------------------------------------------------------- System initialization function *----------------------------------------------------------------------------*/ void SystemInit (void) { #if defined (__VTOR_PRESENT) && (__VTOR_PRESENT == 1U) SCB->VTOR = (uint32_t) &__Vectors; #endif #if defined (__FPU_USED) && (__FPU_USED == 1U) SCB->CPACR |= ((3U << 10U*2U) | /* enable CP10 Full Access */ (3U << 11U*2U) ); /* enable CP11 Full Access */ #endif #ifdef UNALIGNED_SUPPORT_DISABLE SCB->CCR |= SCB_CCR_UNALIGN_TRP_Msk; #endif SystemCoreClock = SYSTEM_CLOCK; }