Diff: targets/TARGET_STM/TARGET_STM32L0/TARGET_STM32L072xZ/TARGET_DISCO_L072CZ_LRWAN1/system_clock.c

Revision:

181:57724642e740

Parent:

178:79309dc6340a

Child:

187:0387e8f68319

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/targets/TARGET_STM/TARGET_STM32L0/TARGET_STM32L072xZ/TARGET_DISCO_L072CZ_LRWAN1/system_clock.c	Fri Feb 16 16:09:33 2018 +0000
@@ -0,0 +1,283 @@
+/* mbed Microcontroller Library
+* Copyright (c) 2006-2017 ARM Limited
+*
+* 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.
+*/
+
+/**
+  * This file configures the system clock as follows:
+  *-----------------------------------------------------------------
+  * System clock source | 1- USE_PLL_HSE_EXTC (external 8 MHz clock)
+  *                     | 2- USE_PLL_HSE_XTAL (external 8 MHz xtal)
+  *                     | 3- USE_PLL_HSI (internal 16 MHz)
+  *-----------------------------------------------------------------
+  * SYSCLK(MHz)         | 32
+  * AHBCLK (MHz)        | 32
+  * APB1CLK (MHz)       | 32
+  * USB capable         | YES
+  *-----------------------------------------------------------------
+  */
+
+#include "stm32l0xx.h"
+#include "mbed_assert.h"
+
+/*!< Uncomment the following line if you need to relocate your vector Table in
+     Internal SRAM. */
+/* #define VECT_TAB_SRAM */
+#define VECT_TAB_OFFSET  0x00U /*!< Vector Table base offset field.
+                                   This value must be a multiple of 0x100. */
+
+#define USE_PLL_HSE_EXTC     0x8  // Use external clock (ST Link MCO)
+#define USE_PLL_HSE_XTAL     0x4  // Use external xtal (X3 on board - not provided by default)
+#define USE_PLL_HSI          0x2  // Use HSI internal clock
+
+// Uncomment to output the MCO on PA8 for debugging
+//#define DEBUG_MCO
+
+#if ( ((CLOCK_SOURCE) & USE_PLL_HSE_XTAL) || ((CLOCK_SOURCE) & USE_PLL_HSE_EXTC) )
+uint8_t SetSysClock_PLL_HSE(uint8_t bypass);
+#endif /* ((CLOCK_SOURCE) & USE_PLL_HSE_XTAL) || ((CLOCK_SOURCE) & USE_PLL_HSE_EXTC) */
+
+#if ((CLOCK_SOURCE) & USE_PLL_HSI)
+uint8_t SetSysClock_PLL_HSI(void);
+#endif /* ((CLOCK_SOURCE) & USE_PLL_HSI) */
+
+
+/**
+  * @brief  Setup the microcontroller system.
+  * @param  None
+  * @retval None
+  */
+void SystemInit (void)
+{
+    /*!< Set MSION bit */
+    RCC->CR |= (uint32_t)0x00000100U;
+
+    /*!< Reset SW[1:0], HPRE[3:0], PPRE1[2:0], PPRE2[2:0], MCOSEL[2:0] and MCOPRE[2:0] bits */
+    RCC->CFGR &= (uint32_t) 0x88FF400CU;
+
+    /*!< Reset HSION, HSIDIVEN, HSEON, CSSON and PLLON bits */
+    RCC->CR &= (uint32_t)0xFEF6FFF6U;
+
+    /*!< Reset HSI48ON  bit */
+    RCC->CRRCR &= (uint32_t)0xFFFFFFFEU;
+
+    /*!< Reset HSEBYP bit */
+    RCC->CR &= (uint32_t)0xFFFBFFFFU;
+
+    /*!< Reset PLLSRC, PLLMUL[3:0] and PLLDIV[1:0] bits */
+    RCC->CFGR &= (uint32_t)0xFF02FFFFU;
+
+    /*!< Disable all interrupts */
+    RCC->CIER = 0x00000000U;
+
+    /* Configure the Vector Table location add offset address ------------------*/
+#ifdef VECT_TAB_SRAM
+    SCB->VTOR = SRAM_BASE | VECT_TAB_OFFSET; /* Vector Table Relocation in Internal SRAM */
+#else
+    SCB->VTOR = FLASH_BASE | VECT_TAB_OFFSET; /* Vector Table Relocation in Internal FLASH */
+#endif
+
+}
+
+/**
+  * @brief  Configures the System clock source, PLL Multiplier and Divider factors,
+  *               AHB/APBx prescalers and Flash settings
+  * @note   This function should be called only once the RCC clock configuration
+  *         is reset to the default reset state (done in SystemInit() function).
+  * @param  None
+  * @retval None
+  */
+void SetSysClock(void)
+{
+#if ((CLOCK_SOURCE) & USE_PLL_HSE_EXTC)
+    /* 1- Try to start with HSE and external clock */
+    if (SetSysClock_PLL_HSE(1) == 0)
+#endif
+    {
+#if ((CLOCK_SOURCE) & USE_PLL_HSE_XTAL)
+        /* 2- If fail try to start with HSE and external xtal */
+        if (SetSysClock_PLL_HSE(0) == 0)
+#endif
+        {
+#if ((CLOCK_SOURCE) & USE_PLL_HSI)
+            /* 3- If fail start with HSI clock */
+            if (SetSysClock_PLL_HSI() == 0)
+#endif
+            {
+                while(1) {
+                    MBED_ASSERT(1);
+                }
+            }
+        }
+    }
+}
+
+#if ( ((CLOCK_SOURCE) & USE_PLL_HSE_XTAL) || ((CLOCK_SOURCE) & USE_PLL_HSE_EXTC) )
+/******************************************************************************/
+/*            PLL (clocked by HSE) used as System clock source                */
+/******************************************************************************/
+uint8_t SetSysClock_PLL_HSE(uint8_t bypass)
+{
+    RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
+    RCC_OscInitTypeDef RCC_OscInitStruct = {0};
+    RCC_PeriphCLKInitTypeDef RCC_PeriphClkInit = {0};
+    RCC_CRSInitTypeDef RCC_CRSInitStruct = {0};
+
+    /* Used to gain time after DeepSleep in case HSI is used */
+    if (__HAL_RCC_GET_FLAG(RCC_FLAG_HSIRDY) != RESET) {
+        return 0;
+    }
+
+    /* The voltage scaling allows optimizing the power consumption when the device is
+       clocked below the maximum system frequency, to update the voltage scaling value
+       regarding system frequency refer to product datasheet. */
+    __PWR_CLK_ENABLE();
+    __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);
+    __HAL_RCC_PWR_CLK_DISABLE();
+
+    /* Enable HSE and HSI48 oscillators and activate PLL with HSE as source */
+    RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE | RCC_OSCILLATORTYPE_HSI | RCC_OSCILLATORTYPE_HSI48;
+    if (bypass == 0) {
+        RCC_OscInitStruct.HSEState          = RCC_HSE_ON; /* 8 MHz xtal on OSC_IN/OSC_OUT */
+    } else {
+        RCC_OscInitStruct.HSEState          = RCC_HSE_BYPASS; /* External 8 MHz clock on OSC_IN */
+    }
+    RCC_OscInitStruct.HSIState            = RCC_HSI_OFF;
+    RCC_OscInitStruct.HSI48State          = RCC_HSI48_ON; /* For USB and RNG clock */
+    // PLLCLK = (8 MHz * 8)/2 = 32 MHz
+    RCC_OscInitStruct.PLL.PLLState        = RCC_PLL_ON;
+    RCC_OscInitStruct.PLL.PLLSource       = RCC_PLLSOURCE_HSE;
+    RCC_OscInitStruct.PLL.PLLMUL          = RCC_PLLMUL_8;
+    RCC_OscInitStruct.PLL.PLLDIV          = RCC_PLLDIV_2;
+    if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK) {
+        return 0; // FAIL
+    }
+
+    /* Select HSI48 as USB clock source */
+    RCC_PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_USB;
+    RCC_PeriphClkInit.UsbClockSelection = RCC_USBCLKSOURCE_HSI48;
+    if (HAL_RCCEx_PeriphCLKConfig(&RCC_PeriphClkInit) != HAL_OK) {
+        return 0; // FAIL
+    }
+    
+    /* Select PLL as system clock source and configure the HCLK, PCLK1 and PCLK2 clocks dividers */
+    RCC_ClkInitStruct.ClockType      = (RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_PCLK1 | RCC_CLOCKTYPE_PCLK2);
+    RCC_ClkInitStruct.SYSCLKSource   = RCC_SYSCLKSOURCE_PLLCLK; // 32 MHz
+    RCC_ClkInitStruct.AHBCLKDivider  = RCC_SYSCLK_DIV1;         // 32 MHz
+    RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;           // 32 MHz
+    RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;           // 32 MHz
+    if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_1) != HAL_OK) {
+        return 0; // FAIL
+    }
+
+    /* Configure the clock recovery system (CRS) ********************************/
+    /* Enable CRS Clock */
+    __HAL_RCC_CRS_CLK_ENABLE();
+    /* Default Synchro Signal division factor (not divided) */
+    RCC_CRSInitStruct.Prescaler = RCC_CRS_SYNC_DIV1;
+    /* Set the SYNCSRC[1:0] bits according to CRS_Source value */
+    RCC_CRSInitStruct.Source = RCC_CRS_SYNC_SOURCE_USB;
+    /* HSI48 is synchronized with USB SOF at 1KHz rate */
+    RCC_CRSInitStruct.ReloadValue = __HAL_RCC_CRS_RELOADVALUE_CALCULATE(48000000, 1000);
+    RCC_CRSInitStruct.ErrorLimitValue = RCC_CRS_ERRORLIMIT_DEFAULT;
+    /* Set the TRIM[5:0] to the default value */
+    RCC_CRSInitStruct.HSI48CalibrationValue = 0x20;
+    /* Start automatic synchronization */
+    HAL_RCCEx_CRSConfig(&RCC_CRSInitStruct);
+
+#ifdef DEBUG_MCO
+    // Output clock on MCO1 pin(PA8) for debugging purpose
+    if (bypass == 0) { // Xtal used
+        HAL_RCC_MCOConfig(RCC_MCO1, RCC_MCO1SOURCE_SYSCLK, RCC_MCODIV_2); // 16 MHz
+    }
+    else { // External clock used
+        HAL_RCC_MCOConfig(RCC_MCO1, RCC_MCO1SOURCE_SYSCLK, RCC_MCODIV_4); // 8 MHz
+    }
+#endif
+
+    return 1; // OK
+}
+#endif /* ((CLOCK_SOURCE) & USE_PLL_HSE_XTAL) || ((CLOCK_SOURCE) & USE_PLL_HSE_EXTC) */
+
+#if ((CLOCK_SOURCE) & USE_PLL_HSI)
+/******************************************************************************/
+/*            PLL (clocked by HSI) used as System clock source                */
+/******************************************************************************/
+uint8_t SetSysClock_PLL_HSI(void)
+{
+    RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
+    RCC_OscInitTypeDef RCC_OscInitStruct = {0};
+    RCC_PeriphCLKInitTypeDef PeriphClkInitStruct = {0};
+    RCC_CRSInitTypeDef RCC_CRSInitStruct = {0};
+
+    /* The voltage scaling allows optimizing the power consumption when the device is
+       clocked below the maximum system frequency, to update the voltage scaling value
+       regarding system frequency refer to product datasheet. */
+    __HAL_RCC_PWR_CLK_ENABLE();
+    __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);
+    __HAL_RCC_PWR_CLK_DISABLE();
+
+    /* Enable HSI and HSI48 oscillators and activate PLL with HSI as source */
+    RCC_OscInitStruct.OscillatorType      = RCC_OSCILLATORTYPE_HSE | RCC_OSCILLATORTYPE_HSI | RCC_OSCILLATORTYPE_HSI48;
+    RCC_OscInitStruct.HSEState            = RCC_HSE_OFF;
+    RCC_OscInitStruct.HSIState            = RCC_HSI_ON;
+    RCC_OscInitStruct.HSI48State          = RCC_HSI48_ON; /* For USB and RNG clock */
+    RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
+    // PLLCLK = (16 MHz * 6)/3 = 32 MHz
+    RCC_OscInitStruct.PLL.PLLState        = RCC_PLL_ON;
+    RCC_OscInitStruct.PLL.PLLSource       = RCC_PLLSOURCE_HSI;
+    RCC_OscInitStruct.PLL.PLLMUL          = RCC_PLLMUL_6;
+    RCC_OscInitStruct.PLL.PLLDIV          = RCC_PLLDIV_3;
+    if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK) {
+        return 0; // FAIL
+    }
+
+    /* Select HSI48 as USB clock source */
+    PeriphClkInitStruct.PeriphClockSelection = RCC_PERIPHCLK_USB;
+    PeriphClkInitStruct.UsbClockSelection = RCC_USBCLKSOURCE_HSI48;
+    HAL_RCCEx_PeriphCLKConfig(&PeriphClkInitStruct);
+
+    /* Select PLL as system clock source and configure the HCLK, PCLK1 and PCLK2 clocks dividers */
+    RCC_ClkInitStruct.ClockType      = (RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_PCLK1 | RCC_CLOCKTYPE_PCLK2);
+    RCC_ClkInitStruct.SYSCLKSource   = RCC_SYSCLKSOURCE_PLLCLK; // 32 MHz
+    RCC_ClkInitStruct.AHBCLKDivider  = RCC_SYSCLK_DIV1;         // 32 MHz
+    RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;           // 32 MHz
+    RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;           // 32 MHz
+    if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_1) != HAL_OK) {
+        return 0; // FAIL
+    }
+
+    /* Configure the clock recovery system (CRS) ********************************/
+    /* Enable CRS Clock */
+    __HAL_RCC_CRS_CLK_ENABLE();
+    /* Default Synchro Signal division factor (not divided) */
+    RCC_CRSInitStruct.Prescaler = RCC_CRS_SYNC_DIV1;
+    /* Set the SYNCSRC[1:0] bits according to CRS_Source value */
+    RCC_CRSInitStruct.Source = RCC_CRS_SYNC_SOURCE_USB;
+    /* HSI48 is synchronized with USB SOF at 1KHz rate */
+    RCC_CRSInitStruct.ReloadValue = __HAL_RCC_CRS_RELOADVALUE_CALCULATE(48000000, 1000);
+    RCC_CRSInitStruct.ErrorLimitValue = RCC_CRS_ERRORLIMIT_DEFAULT;
+    /* Set the TRIM[5:0] to the default value */
+    RCC_CRSInitStruct.HSI48CalibrationValue = 0x20;
+    /* Start automatic synchronization */
+    HAL_RCCEx_CRSConfig(&RCC_CRSInitStruct);
+
+#ifdef DEBUG_MCO
+    // Output clock on MCO1 pin(PA8) for debugging purpose
+    HAL_RCC_MCOConfig(RCC_MCO1, RCC_MCO1SOURCE_SYSCLK, RCC_MCODIV_1); // 32 MHz (not precise due to HSI not calibrated)
+#endif
+
+    return 1; // OK
+}
+#endif /* ((CLOCK_SOURCE) & USE_PLL_HSI) */