How to increase freq of MCU to 480MHz?

StaffanMelin · September 25, 2021, 7:11am

How do I raise the MCU frequency to 480MHz?

Can I just change

    void Defaults()
    {
        cpu_freq   = SysClkFreq::FREQ_400MHZ;
        use_dcache = true;
        use_icache = true;
    }

to FREQ_480MHZ in

libdaisy/src/sys/system.h

and it will work?

I am curious what these extra 80/400 % clock cycles will mean for my code (specifically, more running oscillators)!

Will that introduce any problems with DaisySP and/or libdaisy, timing issues etc?

antisvin · September 25, 2021, 8:23am

There’s no need to edit libdaisy sources. The proper way to use it is by setting boost = true when you init the board in your patch:

github.com

electro-smith/libDaisy/blob/master/src/daisy_seed.h#L46


      
          for a specific application.
          */
          void Init(bool boost = false);
          
          /** 
          Deinitializes all peripherals automatically handled by `Init`.
          */
          void DeInit();
          
          /** 
          Wait some ms before going on.
          \param del Delay time in ms.
          */
          void DelayMs(size_t del);
          
          /** 
          Returns the gpio_pin corresponding to the index 0-31.
          For the given GPIO on the Daisy Seed (labeled 1-32 in docs).
          */
          static dsy_gpio_pin GetPin(uint8_t pin_idx);

Yup, 20% more oscillators at your service. I’m not aware of anyone running into problems from running it on 480Mhz, but that would obviously increase power dissipation to some extent.

StaffanMelin · September 25, 2021, 8:39am

Thank you for your quick answer, @antisvin! (Somehow I knew that you would be the first to anwer this. )

Seems very simple, I’ll try it right away!

StaffanMelin · September 25, 2021, 9:08am

This worked fine!