HFXO control while using Radio

[tc_2020]

Hello,

Is that true I only need the HFXO to be on right before issuing NRF_RADIO->TASKS_START = 1?

As long as the radio is not in TX/RX status, the HFXO can be turned off?

Thanks!

[Vidar Berg]

Hello,

Yes, that is correct, and you can turn off the crystal afterwards to lower the idle current. Just remember to take the HFXO startup time into account to be sure the the clock is ready before you start the RADIO. For comparison, our Softdevice (Bluetooth stack) ramps up the crystal about 1.5 ms prior to radio activity

[tc_2020]

Sorry, I read the wrong bit. So the HFCLK is running actually, but not using HFXO after issuing HFCLKSTARTED task.