RCC HAL module driver. This file provides firmware functions to manage the following functionalities of the Reset and Clock Control (RCC) peripheral: More...
#include "stm32f7xx_hal.h"
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RCC HAL module driver. This file provides firmware functions to manage the following functionalities of the Reset and Clock Control (RCC) peripheral:
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##### RCC specific features #####
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[..]
After reset the device is running from Internal High Speed oscillator
(HSI 16MHz) with Flash 0 wait state, Flash prefetch buffer, D-Cache
and I-Cache are disabled, and all peripherals are off except internal
SRAM, Flash and JTAG.
(+) There is no prescaler on High speed (AHB) and Low speed (APB) busses;
all peripherals mapped on these busses are running at HSI speed.
(+) The clock for all peripherals is switched off, except the SRAM and FLASH.
(+) All GPIOs are in input floating state, except the JTAG pins which
are assigned to be used for debug purpose.
[..]
Once the device started from reset, the user application has to:
(+) Configure the clock source to be used to drive the System clock
(if the application needs higher frequency/performance)
(+) Configure the System clock frequency and Flash settings
(+) Configure the AHB and APB busses prescalers
(+) Enable the clock for the peripheral(s) to be used
(+) Configure the clock source(s) for peripherals which clocks are not
derived from the System clock (I2S, RTC, ADC, USB OTG FS/SDIO/RNG)
##### RCC Limitations #####
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[..]
A delay between an RCC peripheral clock enable and the effective peripheral
enabling should be taken into account in order to manage the peripheral read/write
from/to registers.
(+) This delay depends on the peripheral mapping.
(+) If peripheral is mapped on AHB: the delay is 2 AHB clock cycle
after the clock enable bit is set on the hardware register
(+) If peripheral is mapped on APB: the delay is 2 APB clock cycle
after the clock enable bit is set on the hardware register
[..]
Implemented Workaround:
(+) For AHB & APB peripherals, a dummy read to the peripheral register has been
inserted in each __HAL_RCC_PPP_CLK_ENABLE() macro.This software component is licensed by ST under BSD 3-Clause license, the "License"; You may not use this file except in compliance with the License. You may obtain a copy of the License at: opensource.org/licenses/BSD-3-Clause
Definition in file stm32f7xx_hal_rcc.c.