Generating high frequency clock on gpio

[kbj]

Hi, I'm a beginner for nrf52840 development.

As I know the ARM core operates on 64MHz clock.

So I think there is 64 MHz clock in this board.

My question is the followings

- Is there 64MHz clock signal in nrf52840?

- Can I extract the 64MHz clock signal through gpio?

- If not, how much is the maximum frequency that I can use through gpio pin?

[Daniel Chisholm]

Yes.

No.

The highest frequency available to the GPIO and also the GPIOTE peripherals is 16MHz.  This can be used to trigger a GPIO "TOGGLE" task, so it is possible to create an 8MHz signal on a GPIO pin.