Diff: targets/cmsis/TARGET_NORDIC/TARGET_MCU_NRF51822/system_nrf51822.c

Revision:

270:e2babe29baf8

Parent:

127:ce7cebc0511f

Child:

304:89b9c3a9a045

diff -r 0e58554f11d5 -r e2babe29baf8 targets/cmsis/TARGET_NORDIC/TARGET_MCU_NRF51822/system_nrf51822.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/targets/cmsis/TARGET_NORDIC/TARGET_MCU_NRF51822/system_nrf51822.c	Fri Aug 01 14:45:06 2014 +0100
@@ -0,0 +1,107 @@
+/* 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 16 MHz crystal oscillator.
+    NRF_CLOCK->EVENTS_HFCLKSTARTED  = 0;
+    NRF_CLOCK->TASKS_HFCLKSTART     = 1;
+
+    // Wait for the external oscillator to start up.
+    while (NRF_CLOCK->EVENTS_HFCLKSTARTED == 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;
+}
+