In SX Microcontrollers, SX/B Compiler and SX-Key Tool, phipi wrote:

Peter,

The noise immunity issue I posited has nothing to do with the leakage current. They are separate issues. Even with zero leakage current, noise immunity is a valid reason for favoring lower-valued pullup resistors. Obviously, in a benign, noiseless environment with zero input leakage, even a 10M resistor would be adequate to hold the SX out of reset. I've yet to experience such an environment in real life, though. Besides, with zero leakage, the pullup value isn't "virtually irrelevant" to to power consumption, as I pointed out above; it's [i]completely[/i] irrelevant. As such, I'm hard-pressed to think of a valid reason to use more than 10K, unless some capacitance is added to the /MCLR pin, which also increase noise immunity. (There isn't a spec for maximum /MCLR rise time, BTW — only for Vdd rise time.) 

-Phil

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