I am confused with the clock system on my STM32F7 device (Cortex-M7 microcontroller from STMicroelectronics). The reference manual does not clarify the differences between these clocks sufficiently:
The reference manual reads in chapter << 5.2 Clocks >> "The RCC feeds the external clock of the Cortex System Timer (SysTick) with the AHB clock (HCLK) divided by 8."
This statement contradicts the figure from CubeMX. Notice that in CubeMX I can choose myself the prescaler from HCLK to 'Cortex System Timer'. It is not necessarily a division by 8.
Normally the only difference between HCLK
and FCLK
is that :
HCLK
is the main CPU clock, also used for AHB interface. It can be gated when the CPU is sleeping (WFI for example)FCLK
is synchronous to HCLK
but is not gated when the CPU goes to sleep, so that it can awake in case of interrupt.