Why doesn't analogWrite() protect its writes to 16bit registers?

[DaveX]

@johnwasser

Note also: The masking takes place at the time of writing the registers so set WGM before initializing TCNT1, OCR1A, or OCR1B if you don't want the top bits of your value accidentally masked off.

I thought this was backward, but you mean that you should configure a non-8,9,10 bit WGM mode, like WGM=0, before initializing the registers so they don't get masked.

@johnwasser

in 8, 9, and 10-bit modes. But not when writing to ICR1.

I noticed this section in the ATMega datasheet that seems to say ICRn can only be written in modes that use ICRn for TOP, not the 8,9,10 bit modes: