mbed library sources
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targets/cmsis/TARGET_NORDIC/TARGET_MCU_NRF51822/system_nrf51822.c
- Committer:
- mbed_official
- Date:
- 2014-08-29
- Revision:
- 304:89b9c3a9a045
- Parent:
- 270:e2babe29baf8
- Child:
- 306:d33324c3b5a2
File content as of revision 304:89b9c3a9a045:
/* mbed Microcontroller Library * Copyright (c) 2013 Nordic Semiconductor. * * 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 * * http://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. */ #include <stdint.h> #include <stdbool.h> #include "nrf51822.h" #include "system_nrf51822.h" #define __SYSTEM_CLOCK (16000000UL) //!< nRF51 devices use a fixed System Clock Frequency of 16MHz static bool is_manual_peripheral_setup_needed(void); static bool is_disabled_in_debug_needed(void); #if defined ( __CC_ARM ) uint32_t SystemCoreClock __attribute__((used)) = __SYSTEM_CLOCK; #elif defined ( __ICCARM__ ) __root uint32_t SystemCoreClock = __SYSTEM_CLOCK; #elif defined ( __GNUC__ ) uint32_t SystemCoreClock __attribute__((used)) = __SYSTEM_CLOCK; #endif void SystemCoreClockUpdate(void) { SystemCoreClock = __SYSTEM_CLOCK; } void SystemInit(void) { // Prepare the peripherals for use as indicated by the PAN 26 "System: Manual setup is required // to enable the use of peripherals" found at Product Anomaly document for your device found at // https://www.nordicsemi.com/. The side effect of executing these instructions in the devices // that do not need it is that the new peripherals in the second generation devices (LPCOMP for // example) will not be available. if (is_manual_peripheral_setup_needed()){ *(uint32_t volatile *)0x40000504 = 0xC007FFDF; *(uint32_t volatile *)0x40006C18 = 0x00008000; } // Disable PROTENSET registers under debug, as indicated by PAN 59 "MPU: Reset value of DISABLEINDEBUG // register is incorrect" found at Product Anomaly document four your device found at // https://www.nordicsemi.com/. There is no side effect of using these instruction if not needed. if (is_disabled_in_debug_needed()){ NRF_MPU->DISABLEINDEBUG = MPU_DISABLEINDEBUG_DISABLEINDEBUG_Disabled << MPU_DISABLEINDEBUG_DISABLEINDEBUG_Pos; } // Start the external 32khz crystal oscillator. NRF_CLOCK->LFCLKSRC = (CLOCK_LFCLKSRC_SRC_Xtal << CLOCK_LFCLKSRC_SRC_Pos); NRF_CLOCK->EVENTS_LFCLKSTARTED = 0; NRF_CLOCK->TASKS_LFCLKSTART = 1; // Wait for the external oscillator to start up. while (NRF_CLOCK->EVENTS_LFCLKSTARTED == 0) { // Do nothing. } } static bool is_manual_peripheral_setup_needed(void) { if ((((*(uint32_t *)0xF0000FE0) & 0x000000FF) == 0x1) && (((*(uint32_t *)0xF0000FE4) & 0x0000000F) == 0x0)) { if ((((*(uint32_t *)0xF0000FE8) & 0x000000F0) == 0x00) && (((*(uint32_t *)0xF0000FEC) & 0x000000F0) == 0x0)) { return true; } if ((((*(uint32_t *)0xF0000FE8) & 0x000000F0) == 0x10) && (((*(uint32_t *)0xF0000FEC) & 0x000000F0) == 0x0)) { return true; } if ((((*(uint32_t *)0xF0000FE8) & 0x000000F0) == 0x30) && (((*(uint32_t *)0xF0000FEC) & 0x000000F0) == 0x0)) { return true; } } return false; } static bool is_disabled_in_debug_needed(void) { if ((((*(uint32_t *)0xF0000FE0) & 0x000000FF) == 0x1) && (((*(uint32_t *)0xF0000FE4) & 0x0000000F) == 0x0)) { if ((((*(uint32_t *)0xF0000FE8) & 0x000000F0) == 0x40) && (((*(uint32_t *)0xF0000FEC) & 0x000000F0) == 0x0)) { return true; } } return false; }