AN2994 - SCH322x PCB Schematic Review Checklist - Clarifications

Should there be pull-up or pull-down resistors to the power planes for all signals including clock, connected pins, and pins denoted as NC?

Yes, there should be pull-up or pull-down resistors to the power planes for all signals including clock as this is strongly recommended for those pins that default as input signals. However, they are NOT required for outputs. This is to avoid floating pins that can cause power leakage or undetermined states to the hardware blocks.

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