running nrf 52832 with external 16 MHz crystal

RE: running nrf 52832 with external 16 MHz crystal

yaron — Mon, 02 Nov 2015 12:30:27 GMT

Hi Martin. Thanks for your answer. You are basicly correct, my porpuse is to save current. But since in my code I have some built-in delays (in which lower clock would consume less current), I wanted to test running in lower clock.

RE: running nrf 52832 with external 16 MHz crystal

MartinBL — Mon, 02 Nov 2015 10:00:47 GMT

Sorry for the late response. We chose not to implement a clock divider because we found 64MHz to be most effective in terms of current consumption and hence we didn't see the need for a clock divider. Using a 64MHz clock will of course execute your tasks faster and overall you want save power reducing the clock speed. Out of curiosity, do your a different reason to reduce the clock speed?

RE: running nrf 52832 with external 16 MHz crystal

yaron — Thu, 22 Oct 2015 14:27:13 GMT

Hi Martin

I just wonder, why can't the CPU run at 32 MHz? Thanks again

RE: running nrf 52832 with external 16 MHz crystal

MartinBL — Thu, 22 Oct 2015 13:46:28 GMT

Simple answers:

You have to use a 32MHz crystal (16MHz crystals are no longer an option as it used to be on the nRF51).
You can only run the CPU at 64MHz.