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Changing the core frequency

Posted: Wed May 10, 2017 12:12 pm
by andi0109
Hello

I'm using the AT91SAMA5D21 controller. I would like to change the core cpu clock to a lower frequency value. I think the CPU is usually running with 498 MHz.
Which software part is responsible for setting the clock frequency?
Is it u-boot or is it the Linux kernel?

Maybe someone can point me into the right direction.

Thanks,
Andreas

Re: Changing the core frequency

Posted: Thu May 11, 2017 12:37 am
by blue_z
andi0109 wrote:Which software part is responsible for setting the clock frequency?
If you want to change the MPU clock, then it has to be done in AT91Bootstrap, and also propagate that change to U-Boot and the Linux kernel.
Look for a MASTER_CLOCK (or similar) definition in each program and the kernel.

Regards