stmclk.h File Reference

Interface for configuring the clock tree of STM32 CPUs. More...

Detailed Description

Interface for configuring the clock tree of STM32 CPUs.

Todo:
This interface should probably be moved and implemented for every STM32 CPU
Author
Hauke Petersen hauke.nosp@m..per.nosp@m.terse.nosp@m.n@fu.nosp@m.-berl.nosp@m.in.d.nosp@m.e

Definition in file stmclk.h.

Go to the source code of this file.

Functions

void stmclk_init_sysclk (void)
 Configure the high speed clock domain (main system clock) More...
 
void stmclk_enable_hsi (void)
 Enable the internal high speed clock (HSI)
 
void stmclk_disable_hsi (void)
 Disable the internal high speed clock (HSI) More...
 
void stmclk_enable_lfclk (void)
 Configure and enable the low speed clock domain. More...
 
void stmclk_disable_lfclk (void)
 Disable the low frequency clock domain. More...
 
void stmclk_dbp_unlock (void)
 Unlock write access to the backup domain control.
 
void stmclk_dbp_lock (void)
 Lock write access to backup control domain.
 

Function Documentation

◆ stmclk_disable_hsi()

void stmclk_disable_hsi ( void  )

Disable the internal high speed clock (HSI)

Note
The HSI is only disabled, if it is at that point not used to drive the system clock or the PLL

◆ stmclk_disable_lfclk()

void stmclk_disable_lfclk ( void  )

Disable the low frequency clock domain.

Note
When calling this function, better know what you do: be sure that the clock is not needed by any peripheral before calling this function.

◆ stmclk_enable_lfclk()

void stmclk_enable_lfclk ( void  )

Configure and enable the low speed clock domain.

The actual clock used as input for the low frequency clock can be either the external low speed clock (LSE) or the internal low speed clock (LSI). This is configured in the board's periph_conf.h file.

◆ stmclk_init_sysclk()

void stmclk_init_sysclk ( void  )

Configure the high speed clock domain (main system clock)

This function initializes and configures the main systems clock(s). For this, the following actions are carried out:

  • enable the HSI
  • use the HSI as system clock (so now we are always in a defined state)
  • configure flash wait states and AHB/APB bus dividers
  • [opt] enable the HSE / MSI
  • configure the PLL
  • use PLL as system clock
  • turn off the HSI if unused

All of these options are configurable through the board's periph_conf.h