Zakaria ElQotbi / mbed-src

mbed library sources for airmote

Fork of mbed-src by mbed official

targets/cmsis/TARGET_NORDIC/TARGET_MCU_NRF51822/system_nrf51.c@603:3c75ef011213, 2015-08-13 (annotated)

Committer:
mbed_official
Date:
Thu Aug 13 10:30:09 2015 +0100
Revision:
603:3c75ef011213
Parent:
598:2d5fc5624619
Child:
620:49241b7c6da5
Synchronized with git revision 7cbf9896cc73d825b242028a5f95030a9e1016a4



Full URL: https://github.com/mbedmicro/mbed/commit/7cbf9896cc73d825b242028a5f95030a9e1016a4/



Added requirements.txt file

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mbed_official 501:36015dec7d16 1 /* Copyright (c) 2013, Nordic Semiconductor ASA
mbed_official 501:36015dec7d16 2 * All rights reserved.
mbed_official 501:36015dec7d16 3 *
mbed_official 501:36015dec7d16 4 * Redistribution and use in source and binary forms, with or without
mbed_official 501:36015dec7d16 5 * modification, are permitted provided that the following conditions are met:
mbed_official 501:36015dec7d16 6 *
mbed_official 501:36015dec7d16 7 * * Redistributions of source code must retain the above copyright notice, this
mbed_official 501:36015dec7d16 8 * list of conditions and the following disclaimer.
mbed_official 501:36015dec7d16 9 *
mbed_official 501:36015dec7d16 10 * * Redistributions in binary form must reproduce the above copyright notice,
mbed_official 501:36015dec7d16 11 * this list of conditions and the following disclaimer in the documentation
mbed_official 501:36015dec7d16 12 * and/or other materials provided with the distribution.
mbed_official 501:36015dec7d16 13 *
mbed_official 501:36015dec7d16 14 * * Neither the name of Nordic Semiconductor ASA nor the names of its
mbed_official 501:36015dec7d16 15 * contributors may be used to endorse or promote products derived from
mbed_official 501:36015dec7d16 16 * this software without specific prior written permission.
mbed_official 501:36015dec7d16 17 *
mbed_official 501:36015dec7d16 18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
mbed_official 501:36015dec7d16 19 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
mbed_official 501:36015dec7d16 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
mbed_official 501:36015dec7d16 21 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
mbed_official 501:36015dec7d16 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
mbed_official 501:36015dec7d16 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
mbed_official 501:36015dec7d16 24 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
mbed_official 501:36015dec7d16 25 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
mbed_official 501:36015dec7d16 26 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
mbed_official 501:36015dec7d16 27 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
mbed_official 501:36015dec7d16 28 *
mbed_official 501:36015dec7d16 29 */
mbed_official 501:36015dec7d16 30
mbed_official 501:36015dec7d16 31 /* NOTE: Template files (including this one) are application specific and therefore expected to
mbed_official 501:36015dec7d16 32 be copied into the application project folder prior to its use! */
mbed_official 501:36015dec7d16 33
mbed_official 501:36015dec7d16 34 #include <stdint.h>
mbed_official 501:36015dec7d16 35 #include <stdbool.h>
mbed_official 501:36015dec7d16 36 #include "nrf.h"
mbed_official 603:3c75ef011213 37 #include "nrf_delay.h"
mbed_official 501:36015dec7d16 38 #include "system_nrf51.h"
mbed_official 501:36015dec7d16 39
mbed_official 501:36015dec7d16 40 /*lint ++flb "Enter library region" */
mbed_official 501:36015dec7d16 41
mbed_official 501:36015dec7d16 42 #define __SYSTEM_CLOCK (16000000UL) /*!< nRF51 devices use a fixed System Clock Frequency of 16MHz */
mbed_official 501:36015dec7d16 43
mbed_official 501:36015dec7d16 44 static bool is_manual_peripheral_setup_needed(void);
mbed_official 501:36015dec7d16 45 static bool is_disabled_in_debug_needed(void);
mbed_official 603:3c75ef011213 46 static void init_clock(void);
mbed_official 501:36015dec7d16 47
mbed_official 501:36015dec7d16 48
mbed_official 501:36015dec7d16 49 #if defined ( __CC_ARM )
mbed_official 501:36015dec7d16 50 uint32_t SystemCoreClock __attribute__((used)) = __SYSTEM_CLOCK;
mbed_official 501:36015dec7d16 51 #elif defined ( __ICCARM__ )
mbed_official 501:36015dec7d16 52 __root uint32_t SystemCoreClock = __SYSTEM_CLOCK;
mbed_official 501:36015dec7d16 53 #elif defined ( __GNUC__ )
mbed_official 501:36015dec7d16 54 uint32_t SystemCoreClock __attribute__((used)) = __SYSTEM_CLOCK;
mbed_official 501:36015dec7d16 55 #endif
mbed_official 501:36015dec7d16 56
mbed_official 501:36015dec7d16 57 void SystemCoreClockUpdate(void)
mbed_official 501:36015dec7d16 58 {
mbed_official 501:36015dec7d16 59 SystemCoreClock = __SYSTEM_CLOCK;
mbed_official 501:36015dec7d16 60 }
mbed_official 501:36015dec7d16 61
mbed_official 501:36015dec7d16 62 void SystemInit(void)
mbed_official 501:36015dec7d16 63 {
mbed_official 501:36015dec7d16 64 /* If desired, switch off the unused RAM to lower consumption by the use of RAMON register.
mbed_official 501:36015dec7d16 65 It can also be done in the application main() function. */
mbed_official 501:36015dec7d16 66
mbed_official 501:36015dec7d16 67 /* Prepare the peripherals for use as indicated by the PAN 26 "System: Manual setup is required
mbed_official 501:36015dec7d16 68 to enable the use of peripherals" found at Product Anomaly document for your device found at
mbed_official 501:36015dec7d16 69 https://www.nordicsemi.com/. The side effect of executing these instructions in the devices
mbed_official 501:36015dec7d16 70 that do not need it is that the new peripherals in the second generation devices (LPCOMP for
mbed_official 501:36015dec7d16 71 example) will not be available. */
mbed_official 501:36015dec7d16 72 if (is_manual_peripheral_setup_needed())
mbed_official 501:36015dec7d16 73 {
mbed_official 501:36015dec7d16 74 *(uint32_t volatile *)0x40000504 = 0xC007FFDF;
mbed_official 501:36015dec7d16 75 *(uint32_t volatile *)0x40006C18 = 0x00008000;
mbed_official 501:36015dec7d16 76 }
mbed_official 501:36015dec7d16 77
mbed_official 501:36015dec7d16 78 /* Disable PROTENSET registers under debug, as indicated by PAN 59 "MPU: Reset value of DISABLEINDEBUG
mbed_official 501:36015dec7d16 79 register is incorrect" found at Product Anomaly document four your device found at
mbed_official 501:36015dec7d16 80 https://www.nordicsemi.com/. There is no side effect of using these instruction if not needed. */
mbed_official 501:36015dec7d16 81 if (is_disabled_in_debug_needed())
mbed_official 501:36015dec7d16 82 {
mbed_official 501:36015dec7d16 83 NRF_MPU->DISABLEINDEBUG = MPU_DISABLEINDEBUG_DISABLEINDEBUG_Disabled << MPU_DISABLEINDEBUG_DISABLEINDEBUG_Pos;
mbed_official 501:36015dec7d16 84 }
mbed_official 501:36015dec7d16 85
mbed_official 501:36015dec7d16 86 // Start the external 32khz crystal oscillator.
mbed_official 603:3c75ef011213 87 init_clock();
mbed_official 603:3c75ef011213 88 }
mbed_official 501:36015dec7d16 89
mbed_official 603:3c75ef011213 90 void init_clock(void)
mbed_official 603:3c75ef011213 91 {
mbed_official 603:3c75ef011213 92 /* For compatibility purpose, the default behaviour is to first attempt to initialise an
mbed_official 603:3c75ef011213 93 external clock, and after a timeout, use the internal RC one. To avoid this wait, boards that
mbed_official 603:3c75ef011213 94 don't have an external oscillator can set TARGET_NRF_LFCLK_RC directly. */
mbed_official 603:3c75ef011213 95 int i = 0;
mbed_official 603:3c75ef011213 96 const uint32_t polling_period = 200;
mbed_official 603:3c75ef011213 97 const uint32_t timeout = 1000000;
mbed_official 603:3c75ef011213 98
mbed_official 598:2d5fc5624619 99 #if defined(TARGET_NRF_LFCLK_RC)
mbed_official 501:36015dec7d16 100 NRF_CLOCK->LFCLKSRC = (CLOCK_LFCLKSRC_SRC_RC << CLOCK_LFCLKSRC_SRC_Pos);
mbed_official 501:36015dec7d16 101 #else
mbed_official 501:36015dec7d16 102 NRF_CLOCK->LFCLKSRC = (CLOCK_LFCLKSRC_SRC_Xtal << CLOCK_LFCLKSRC_SRC_Pos);
mbed_official 501:36015dec7d16 103 #endif
mbed_official 501:36015dec7d16 104 NRF_CLOCK->EVENTS_LFCLKSTARTED = 0;
mbed_official 501:36015dec7d16 105 NRF_CLOCK->TASKS_LFCLKSTART = 1;
mbed_official 501:36015dec7d16 106
mbed_official 603:3c75ef011213 107 /* Wait for the external oscillator to start up.
mbed_official 603:3c75ef011213 108 nRF51822 product specification (8.1.5) gives a typical value of 300ms for external clock
mbed_official 603:3c75ef011213 109 startup duration, and a maximum value of 1s. When using the internal RC source, typical delay
mbed_official 603:3c75ef011213 110 will be 390µs, so we use a polling period of 200µs.
mbed_official 603:3c75ef011213 111
mbed_official 603:3c75ef011213 112 We can't use us_ticker at this point, so we have to rely on a less precise method for
mbed_official 603:3c75ef011213 113 measuring our timeout. Because of this, the actual timeout will be slightly longer than 1
mbed_official 603:3c75ef011213 114 second, which isn't an issue at all, since this fallback should only be used as a safety net.
mbed_official 603:3c75ef011213 115 */
mbed_official 603:3c75ef011213 116 for (i = 0; i < (timeout / polling_period); i++) {
mbed_official 603:3c75ef011213 117 if (NRF_CLOCK->EVENTS_LFCLKSTARTED != 0)
mbed_official 603:3c75ef011213 118 return;
mbed_official 603:3c75ef011213 119 nrf_delay_us(polling_period);
mbed_official 603:3c75ef011213 120 }
mbed_official 603:3c75ef011213 121
mbed_official 603:3c75ef011213 122 /* Fallback to internal clock. Belt and braces, since the internal clock is used by default
mbed_official 603:3c75ef011213 123 whilst no external source is running. This is not only a sanity check, but it also allows
mbed_official 603:3c75ef011213 124 code down the road (e.g. ble initialisation) to directly know which clock is used. */
mbed_official 603:3c75ef011213 125 NRF_CLOCK->LFCLKSRC = (CLOCK_LFCLKSRC_SRC_RC << CLOCK_LFCLKSRC_SRC_Pos);
mbed_official 603:3c75ef011213 126 NRF_CLOCK->TASKS_LFCLKSTART = 1;
mbed_official 501:36015dec7d16 127 while (NRF_CLOCK->EVENTS_LFCLKSTARTED == 0) {
mbed_official 501:36015dec7d16 128 // Do nothing.
mbed_official 501:36015dec7d16 129 }
mbed_official 501:36015dec7d16 130 }
mbed_official 501:36015dec7d16 131
mbed_official 501:36015dec7d16 132 static bool is_manual_peripheral_setup_needed(void)
mbed_official 501:36015dec7d16 133 {
mbed_official 501:36015dec7d16 134 if ((((*(uint32_t *)0xF0000FE0) & 0x000000FF) == 0x1) && (((*(uint32_t *)0xF0000FE4) & 0x0000000F) == 0x0))
mbed_official 501:36015dec7d16 135 {
mbed_official 501:36015dec7d16 136 if ((((*(uint32_t *)0xF0000FE8) & 0x000000F0) == 0x00) && (((*(uint32_t *)0xF0000FEC) & 0x000000F0) == 0x0))
mbed_official 501:36015dec7d16 137 {
mbed_official 501:36015dec7d16 138 return true;
mbed_official 501:36015dec7d16 139 }
mbed_official 501:36015dec7d16 140 if ((((*(uint32_t *)0xF0000FE8) & 0x000000F0) == 0x10) && (((*(uint32_t *)0xF0000FEC) & 0x000000F0) == 0x0))
mbed_official 501:36015dec7d16 141 {
mbed_official 501:36015dec7d16 142 return true;
mbed_official 501:36015dec7d16 143 }
mbed_official 501:36015dec7d16 144 if ((((*(uint32_t *)0xF0000FE8) & 0x000000F0) == 0x30) && (((*(uint32_t *)0xF0000FEC) & 0x000000F0) == 0x0))
mbed_official 501:36015dec7d16 145 {
mbed_official 501:36015dec7d16 146 return true;
mbed_official 501:36015dec7d16 147 }
mbed_official 501:36015dec7d16 148 }
mbed_official 501:36015dec7d16 149
mbed_official 501:36015dec7d16 150 return false;
mbed_official 501:36015dec7d16 151 }
mbed_official 501:36015dec7d16 152
mbed_official 501:36015dec7d16 153 static bool is_disabled_in_debug_needed(void)
mbed_official 501:36015dec7d16 154 {
mbed_official 501:36015dec7d16 155 if ((((*(uint32_t *)0xF0000FE0) & 0x000000FF) == 0x1) && (((*(uint32_t *)0xF0000FE4) & 0x0000000F) == 0x0))
mbed_official 501:36015dec7d16 156 {
mbed_official 501:36015dec7d16 157 if ((((*(uint32_t *)0xF0000FE8) & 0x000000F0) == 0x40) && (((*(uint32_t *)0xF0000FEC) & 0x000000F0) == 0x0))
mbed_official 501:36015dec7d16 158 {
mbed_official 501:36015dec7d16 159 return true;
mbed_official 501:36015dec7d16 160 }
mbed_official 501:36015dec7d16 161 }
mbed_official 501:36015dec7d16 162
mbed_official 501:36015dec7d16 163 return false;
mbed_official 501:36015dec7d16 164 }
mbed_official 501:36015dec7d16 165
mbed_official 501:36015dec7d16 166 /*lint --flb "Leave library region" */