I'm seeing strangeness on my SAME70 clock on a hard reset after power is first applied. I'm expecting the processor to boot using the 4MHz internal RC oscillator, but it seems to be booting with the 12MHz internal RC oscillator instead. All the docs say it comes out of hard reset at 4Mhz. Yes I know docs can be wrong but I'm can't find any reference on the Internet of this change to the default behavior.
An early read of the Main Oscillator Register CKGR_MOR via a call to hri_pmc_read_CKGR_MOR_reg(PMC) as one of the very first instructions in the reset handler shows a value of 0x0000_0028 instead of the expected 0x0000_0008. The difference is MOSCRCF: 4/8/12MHz RC Oscillator Frequency Selection field. As far as I can tell the default value for the processor is selecting the 12MHz RC instead of the expected 4MHz RC.
Is anyone else seeing this? Is it a simple documentation error in my chip ATSAME70Q20? Or is there something I'm missing like perhaps the ability to change the power up default value via some other configuration register?
Yes I know I can switch it very early in the code but quite frankly if I can't trust the default clock settings I can't trust any default register setting. I really don't want to have to program every single register to known values simply because the published defaults are untrustworthy.