Diff: targets/cmsis/TARGET_NORDIC/TARGET_MCU_NRF51822/system_nrf51.c

Revision:

501:36015dec7d16

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/targets/cmsis/TARGET_NORDIC/TARGET_MCU_NRF51822/system_nrf51.c	Tue Apr 07 06:45:07 2015 +0100
@@ -0,0 +1,134 @@
+/* Copyright (c) 2013, Nordic Semiconductor ASA
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *   * Redistributions of source code must retain the above copyright notice, this
+ *     list of conditions and the following disclaimer.
+ *
+ *   * 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.
+ *
+ *   * Neither the name of Nordic Semiconductor ASA nor the names of its
+ *     contributors may be used to endorse or promote products derived from
+ *     this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS 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.
+ *
+ */
+
+/* NOTE: Template files (including this one) are application specific and therefore expected to
+   be copied into the application project folder prior to its use! */
+
+#include <stdint.h>
+#include <stdbool.h>
+#include "nrf.h"
+#include "system_nrf51.h"
+
+/*lint ++flb "Enter library region" */
+
+#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)
+{
+    /* If desired, switch off the unused RAM to lower consumption by the use of RAMON register.
+       It can also be done in the application main() function. */
+
+    /* 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.
+
+#if defined(TARGET_DELTA_DFCM_NNN40) || defined(TARGET_HRM1017)
+    NRF_CLOCK->LFCLKSRC             = (CLOCK_LFCLKSRC_SRC_RC << CLOCK_LFCLKSRC_SRC_Pos);
+#else
+    NRF_CLOCK->LFCLKSRC             = (CLOCK_LFCLKSRC_SRC_Xtal << CLOCK_LFCLKSRC_SRC_Pos);
+#endif
+    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;
+}
+
+/*lint --flb "Leave library region" */