How to use high frequency to run some code?

[john.liu]

hi.

I use nrf52840 sdk nRF5_SDK_17.0.2_d674dde.

I need to control the H and L changes of IO within 300ns, I want to turn on the high-frequency part when necessary, and turn it off after this part runs.

External crystal oscillator 32Mhz.so how to use high frequency to run some code?

Or is there another way?

thank you!

[Vidar Berg]

Hi,

You can call sd_clock_hfclk_request() to make the Softdevice turn on the 32 MHz crystal oscillator when you need a high accuracy clock source, and sd_clock_hfclk_release() when you don't need it any longer (reduces the system IDLE current).

[john.liu]

thanks your for help