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armembeddedmicrocontrolleravrcpu-architecture

Can a Microcontroller peripheral operate with a frequency higher than CPU Freq.?

I wonder if a Microcontroller peripheral can operate with a frequency higher than CPU Freq. Is that possible?

Solution

  • It is entirely part specific - refer to the part's data sheet to reference manual.

    For simple parts such as AVR, probably not (although I have not checked - there are many parts). For parts with complex clock trees such as STM32, certainly. For example:

    enter image description here

    In this example (calculated by ST's deprecated but still useful clock configuration tool), the core clock is 24MHz, while the USB is necessarily run at 48MHz and the I2S at 106.5 MHz. Note also that the I2S can be externally clocked independent of the HSE oscillator used in this example.