diff --git a/radio/src/targets/horus/system_stm32f4xx.c b/radio/src/targets/horus/system_stm32f4xx.c index 3ec7176f5..393603fc2 100644 --- a/radio/src/targets/horus/system_stm32f4xx.c +++ b/radio/src/targets/horus/system_stm32f4xx.c @@ -17,6 +17,116 @@ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ + +/** + ****************************************************************************** + * @file system_stm32f4xx.c + * @author MCD Application Team + * @version V1.1.0 + * @date 21-March-2015 + * @brief CMSIS Cortex-M4 Device Peripheral Access Layer System Source File. + * This file contains the system clock configuration for STM32F4xx devices, + * and is generated by the clock configuration tool + * stm32f4xx_Clock_Configuration_V1.1.0.xls + * + * 1. This file provides two functions and one global variable to be called from + * user application: + * - SystemInit(): Setups the system clock (System clock source, PLL Multiplier + * and Divider factors, AHB/APBx prescalers and Flash settings), + * depending on the configuration made in the clock xls tool. + * This function is called at startup just after reset and + * before branch to main program. This call is made inside + * the "startup_stm32f4xx.s" file. + * + * - SystemCoreClock variable: Contains the core clock (HCLK), it can be used + * by the user application to setup the SysTick + * timer or configure other parameters. + * + * - SystemCoreClockUpdate(): Updates the variable SystemCoreClock and must + * be called whenever the core clock is changed + * during program execution. + * + * 2. After each device reset the HSI (16 MHz) is used as system clock source. + * Then SystemInit() function is called, in "startup_stm32f4xx.s" file, to + * configure the system clock before to branch to main program. + * + * 3. If the system clock source selected by user fails to startup, the SystemInit() + * function will do nothing and HSI still used as system clock source. User can + * add some code to deal with this issue inside the SetSysClock() function. + * + * 4. The default value of HSE crystal is set to 25MHz, refer to "HSE_VALUE" define + * in "stm32f4xx.h" file. When HSE is used as system clock source, directly or + * through PLL, and you are using different crystal you have to adapt the HSE + * value to your own configuration. + * + * 5. This file configures the system clock as follows: + *============================================================================= + *============================================================================= + * Supported STM32F40xx/41xx/427x/437x devices + *----------------------------------------------------------------------------- + * System Clock source | PLL (HSE) + *----------------------------------------------------------------------------- + * SYSCLK(Hz) | 168000000 + *----------------------------------------------------------------------------- + * HCLK(Hz) | 168000000 + *----------------------------------------------------------------------------- + * AHB Prescaler | 1 + *----------------------------------------------------------------------------- + * APB1 Prescaler | 4 + *----------------------------------------------------------------------------- + * APB2 Prescaler | 2 + *----------------------------------------------------------------------------- + * HSE Frequency(Hz) | 12000000 + *----------------------------------------------------------------------------- + * PLL_M | 12 + *----------------------------------------------------------------------------- + * PLL_N | 336 + *----------------------------------------------------------------------------- + * PLL_P | 2 + *----------------------------------------------------------------------------- + * PLL_Q | 7 + *----------------------------------------------------------------------------- + * PLLI2S_N | NA + *----------------------------------------------------------------------------- + * PLLI2S_R | NA + *----------------------------------------------------------------------------- + * I2S input clock | NA + *----------------------------------------------------------------------------- + * VDD(V) | 3.3 + *----------------------------------------------------------------------------- + * Main regulator output voltage | Scale1 mode + *----------------------------------------------------------------------------- + * Flash Latency(WS) | 5 + *----------------------------------------------------------------------------- + * Prefetch Buffer | ON + *----------------------------------------------------------------------------- + * Instruction cache | ON + *----------------------------------------------------------------------------- + * Data cache | ON + *----------------------------------------------------------------------------- + * Require 48MHz for USB OTG FS, | Enabled + * SDIO and RNG clock | + *----------------------------------------------------------------------------- + *============================================================================= + ****************************************************************************** + * @attention + * + *

© COPYRIGHT 2013 STMicroelectronics

+ * + * Licensed under MCD-ST Liberty SW License Agreement V2, (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.st.com/software_license_agreement_liberty_v2 + * + * 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. + * + ****************************************************************************** + */ /** @addtogroup CMSIS * @{