nRF5340 MCK settings

[WesC]

If i set register CONFIG.MCKEN to 1 so Master Clock generator is running and the output is on PSEL.MCK

and in the CONFIG.CLKCONFIG register i set the source to PCLK32M then enable the BYPASS

would i get the PCLK32M clock output directly on the PIN.PORT set in PSEL.MCK?

[helsing]

Hi Wes,

I am looking into this now. I might have to get back to you after the weekend.

Best regards,

Håkon

[WesC]

Thanks.  I guess i will have a follow up question.  DO we know what the maximum MCK frequency we can support on the 5340?  if we enable CONFIG.MCKEN the CONFIG.MCKFREQ register says the values are depreciated and should use the formula.  the formula is not bounded and based on the depreciated values it appears the 16Mhz is the max.  DO we know the real values?

[WesC]

Update to my last comment.  I guess the Formula is bounded by the CONFIG.MCKFREQ register.  the last 12 bit are 0 so the maximum value in that register is 0xFFFFFF00.  using this would give you a maximum output of 32Mhz for MCK.