Quote Originally Posted by richard View Post
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can you make a simplified cut down version that still demonustrates the problem
My usual suggestion, plus, check out the datasheet at the registers just before the messed up one. Anything stand out? Do you use those? Maybe want to display those as well to see if your register is just not the tip that is visible of a larger problem.

Without having a chip to try your code, what about config fuses? Some features multiplex, maybe you've got another feature doing stuff you're not expecting.

Funky stuff, wish I could help.

Robert