system_nrf51.c

00001 /* Copyright (c) 2015, Nordic Semiconductor ASA
00002  * All rights reserved.
00003  *
00004  * Redistribution and use in source and binary forms, with or without
00005  * modification, are permitted provided that the following conditions are met:
00006  *
00007  *   * Redistributions of source code must retain the above copyright notice, this
00008  *     list of conditions and the following disclaimer.
00009  *
00010  *   * Redistributions in binary form must reproduce the above copyright notice,
00011  *     this list of conditions and the following disclaimer in the documentation
00012  *     and/or other materials provided with the distribution.
00013  *
00014  *   * Neither the name of Nordic Semiconductor ASA nor the names of its
00015  *     contributors may be used to endorse or promote products derived from
00016  *     this software without specific prior written permission.
00017  *
00018  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
00019  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
00020  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
00021  * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
00022  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
00023  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
00024  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
00025  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
00026  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
00027  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
00028  *
00029  */
00030 
00031 /* NOTE: Template files (including this one) are application specific and therefore expected to
00032    be copied into the application project folder prior to its use! */
00033 
00034 #include <stdint.h>
00035 #include <stdbool.h>
00036 #include "nrf.h"
00037 #include "system_nrf51.h"
00038 
00039 /*lint ++flb "Enter library region" */
00040 
00041 
00042 #define __SYSTEM_CLOCK      (16000000UL)     /*!< nRF51 devices use a fixed System Clock Frequency of 16MHz */
00043 
00044 static bool is_manual_peripheral_setup_needed(void);
00045 static bool is_disabled_in_debug_needed(void);
00046 static bool is_peripheral_domain_setup_needed(void);
00047 
00048 
00049 #if defined ( __CC_ARM )
00050     uint32_t SystemCoreClock __attribute__((used)) = __SYSTEM_CLOCK;
00051 #elif defined ( __ICCARM__ )
00052     __root uint32_t SystemCoreClock = __SYSTEM_CLOCK;
00053 #elif defined   ( __GNUC__ )
00054     uint32_t SystemCoreClock __attribute__((used)) = __SYSTEM_CLOCK;
00055 #endif
00056 
00057 void SystemCoreClockUpdate(void)
00058 {
00059     SystemCoreClock = __SYSTEM_CLOCK;
00060 }
00061 
00062 void SystemInit(void)
00063 {
00064     /* If desired, switch off the unused RAM to lower consumption by the use of RAMON register.
00065        It can also be done in the application main() function. */
00066 
00067     /* Prepare the peripherals for use as indicated by the PAN 26 "System: Manual setup is required
00068        to enable the use of peripherals" found at Product Anomaly document for your device found at
00069        https://www.nordicsemi.com/. The side effect of executing these instructions in the devices
00070        that do not need it is that the new peripherals in the second generation devices (LPCOMP for
00071        example) will not be available. */
00072     if (is_manual_peripheral_setup_needed())
00073     {
00074         *(uint32_t volatile *)0x40000504 = 0xC007FFDF;
00075         *(uint32_t volatile *)0x40006C18 = 0x00008000;
00076     }
00077 
00078     /* Disable PROTENSET registers under debug, as indicated by PAN 59 "MPU: Reset value of DISABLEINDEBUG
00079        register is incorrect" found at Product Anomaly document for your device found at
00080        https://www.nordicsemi.com/. There is no side effect of using these instruction if not needed. */
00081     if (is_disabled_in_debug_needed())
00082     {
00083         NRF_MPU->DISABLEINDEBUG = MPU_DISABLEINDEBUG_DISABLEINDEBUG_Disabled << MPU_DISABLEINDEBUG_DISABLEINDEBUG_Pos;
00084     }
00085 
00086     /* Execute the following code to eliminate excessive current in sleep mode with RAM retention in nRF51802 devices,
00087        as indicated by PAN 76 "System: Excessive current in sleep mode with retention" found at Product Anomaly document
00088        for your device found at https://www.nordicsemi.com/. */
00089     if (is_peripheral_domain_setup_needed()){
00090         if (*(uint32_t volatile *)0x4006EC00 != 1){
00091             *(uint32_t volatile *)0x4006EC00 = 0x9375;
00092             while (*(uint32_t volatile *)0x4006EC00 != 1){
00093             }
00094         }
00095         *(uint32_t volatile *)0x4006EC14 = 0xC0;
00096     }
00097 }
00098 
00099 
00100 static bool is_manual_peripheral_setup_needed(void)
00101 {
00102     if ((((*(uint32_t *)0xF0000FE0) & 0x000000FF) == 0x1) && (((*(uint32_t *)0xF0000FE4) & 0x0000000F) == 0x0))
00103     {
00104         if ((((*(uint32_t *)0xF0000FE8) & 0x000000F0) == 0x00) && (((*(uint32_t *)0xF0000FEC) & 0x000000F0) == 0x0))
00105         {
00106             return true;
00107         }
00108         if ((((*(uint32_t *)0xF0000FE8) & 0x000000F0) == 0x10) && (((*(uint32_t *)0xF0000FEC) & 0x000000F0) == 0x0))
00109         {
00110             return true;
00111         }
00112         if ((((*(uint32_t *)0xF0000FE8) & 0x000000F0) == 0x30) && (((*(uint32_t *)0xF0000FEC) & 0x000000F0) == 0x0))
00113         {
00114             return true;
00115         }
00116     }
00117 
00118     return false;
00119 }
00120 
00121 static bool is_disabled_in_debug_needed(void)
00122 {
00123     if ((((*(uint32_t *)0xF0000FE0) & 0x000000FF) == 0x1) && (((*(uint32_t *)0xF0000FE4) & 0x0000000F) == 0x0))
00124     {
00125         if ((((*(uint32_t *)0xF0000FE8) & 0x000000F0) == 0x40) && (((*(uint32_t *)0xF0000FEC) & 0x000000F0) == 0x0))
00126         {
00127             return true;
00128         }
00129     }
00130 
00131     return false;
00132 }
00133 
00134 static bool is_peripheral_domain_setup_needed(void)
00135 {
00136     if ((((*(uint32_t *)0xF0000FE0) & 0x000000FF) == 0x1) && (((*(uint32_t *)0xF0000FE4) & 0x0000000F) == 0x0))
00137     {
00138         if ((((*(uint32_t *)0xF0000FE8) & 0x000000F0) == 0xA0) && (((*(uint32_t *)0xF0000FEC) & 0x000000F0) == 0x0))
00139         {
00140             return true;
00141         }
00142         if ((((*(uint32_t *)0xF0000FE8) & 0x000000F0) == 0xD0) && (((*(uint32_t *)0xF0000FEC) & 0x000000F0) == 0x0))
00143         {
00144             return true;
00145         }
00146     }
00147 
00148     return false;
00149 }
00150 
00151 /*lint --flb "Leave library region" */
00152