mbed-os/targets/TARGET_STM/TARGET_STM32F0/TARGET_STM32F091xC/system_clock.c

180 lines
7.4 KiB
C

/* mbed Microcontroller Library
* Copyright (c) 2006-2017 ARM Limited
* SPDX-License-Identifier: Apache-2.0
*
* 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 8 MHz)
*-----------------------------------------------------------------
* SYSCLK(MHz) | 48
* AHBCLK (MHz) | 48
* APB1CLK (MHz) | 48
* USB capable | NO
*-----------------------------------------------------------------
*/
#include "stm32f0xx.h"
#include "mbed_error.h"
#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
#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 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
{
{
error("SetSysClock failed\n");
}
}
}
}
// Output system clock on MCO pin(PA8) for debugging purpose
//HAL_RCC_MCOConfig(RCC_MCO, RCC_MCOSOURCE_SYSCLK, RCC_MCO_DIV8); // 48MHz/8=6MHz
}
#if ( ((CLOCK_SOURCE) & USE_PLL_HSE_XTAL) || ((CLOCK_SOURCE) & USE_PLL_HSE_EXTC) )
/******************************************************************************/
/* PLL (clocked by HSE) used as System clock source */
/******************************************************************************/
MBED_WEAK uint8_t SetSysClock_PLL_HSE(uint8_t bypass)
{
RCC_OscInitTypeDef RCC_OscInitStruct = {0};
RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
__HAL_RCC_SYSCFG_CLK_ENABLE();
//Select HSI as system clock source to allow modification of the PLL configuration
RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_SYSCLK;
RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_HSI;
if(HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_1) != HAL_OK) {
return 0; // FAIL
}
// Select HSE oscillator as PLL source
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
if (bypass == 0) {
RCC_OscInitStruct.HSEState = RCC_HSE_ON; // External 8 MHz xtal on OSC_IN/OSC_OUT
} else {
RCC_OscInitStruct.HSEState = RCC_HSE_BYPASS; // External 8 MHz clock on OSC_IN only
}
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
RCC_OscInitStruct.PLL.PREDIV = RCC_PREDIV_DIV2;
RCC_OscInitStruct.PLL.PLLMUL = RCC_PLL_MUL12;
if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK) {
return 0; // FAIL
}
// Select PLL as system clock source and configure the HCLK and PCLK1 clocks dividers
RCC_ClkInitStruct.ClockType = (RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_PCLK1);
RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK; // 48 MHz
RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1; // 48 MHz
RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1; // 48 MHz
if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_1) != HAL_OK) {
return 0; // FAIL
}
// Output HSE clock on MCO pin(PA8) for debugging purpose
//if (bypass == 0)
// HAL_RCC_MCOConfig(RCC_MCO, RCC_MCOSOURCE_HSE, RCC_MCO_DIV2); // 8MHz/2=4MHz with xtal
//else
// HAL_RCC_MCOConfig(RCC_MCO, RCC_MCOSOURCE_HSE, RCC_MCO_DIV4); // 8MHz/4=2MHz with ST-Link MCO
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_OscInitTypeDef RCC_OscInitStruct;
RCC_ClkInitTypeDef RCC_ClkInitStruct;
__HAL_RCC_SYSCFG_CLK_ENABLE();
// Select PLLCLK = 48 MHz ((HSI 8 MHz / 2) * 12)
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
RCC_OscInitStruct.HSEState = RCC_HSE_OFF;
RCC_OscInitStruct.LSEState = RCC_LSE_OFF;
RCC_OscInitStruct.HSIState = RCC_HSI_ON;
RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
RCC_OscInitStruct.HSI14State = RCC_HSI_OFF;
RCC_OscInitStruct.HSI14CalibrationValue = RCC_HSI14CALIBRATION_DEFAULT;
RCC_OscInitStruct.HSI48State = RCC_HSI_ON;
RCC_OscInitStruct.LSIState = RCC_LSI_OFF;
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSI; // HSI div 2
RCC_OscInitStruct.PLL.PREDIV = RCC_PREDIV_DIV2;
RCC_OscInitStruct.PLL.PLLMUL = RCC_PLL_MUL12;
if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK) {
return 0; // FAIL
}
// Select PLL as system clock source and configure the HCLK and PCLK1 clocks dividers
RCC_ClkInitStruct.ClockType = (RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_PCLK1);
RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK; // 48 MHz
RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1; // 48 MHz
RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1; // 48 MHz
if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_1) != HAL_OK) {
return 0; // FAIL
}
// Output HSI clock on MCO1 pin(PA8) for debugging purpose
//HAL_RCC_MCOConfig(RCC_MCO, RCC_MCOSOURCE_HSI, RCC_MCO_DIV2); // 8MHz/2=4MHz
return 1; // OK
}
#endif /* ((CLOCK_SOURCE) & USE_PLL_HSI) */